GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: MJP on September 17, 2015, 11:48:55 AM
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So this is darkside, and I have been bitten by the bigbore bug. I have built couple of mediocre bore rifles in the past but this is my first real bigbore build. I have got today one of three barrels that have sat in storage greased and unused for decades. Just to be build in to something else that they originally where designed for. It starts with one picture, with one .457 290grain slug for comparison.
(http://i11.aijaa.com/t/00056/13969135.t.jpg) (http://aijaa.com/PpCMrx)
Marko
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:o
I hope you're aware you're gonna need to use an scba tank as a reservoir & more likely than not that gun's only gonna give you one shot.
But oh what a shot it will be 8)
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Oh yeah. Lots of air is going to be used with a dump valve, air is the easiest consumable in this build, think about the size and weight of the lead... With powder the bullet weighed around 120grams...
I was planning on something like half of that.
I'll start with around 800cc air volume in the plenum and work from that to what ever volume is needed for speed.
Edit, the barrel is 1100mm now that I cut the chamber off. Its a 20mm AA gun (anti air gun) ;)
So when you see this Bob Sterne, would you be so kind and tell me some numbers on that air volume in 300bar?
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Accurate has mold which is .755 and 1320grains. It should be possible to get wider like .787 or .788 of course weight increases also ;D
http://www.accuratemolds.com/bullet_detail.php?bullet=75-1320-D.png (http://www.accuratemolds.com/bullet_detail.php?bullet=75-1320-D.png)
It is over two times bigger than mold which I have 683grains :o
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Makes me think about sabots and .50cal slugs... All that surface area and light bullet :D
Marko
Edit, not that 600grains ain't that light to begin with...
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If You can make a sabot I got those .510 and 683 grains casted so that should be good start. ;D or 650 grains...
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No idea what you are considering for velocity.... but here are some idle thoughts to consider.... At 670 fps, you get 1 FPE per grain of bullet weight.... 60 grams is 926 grain, so let's call it 1000 FPE at 700 fps.... My rule of thumb for plenum size is 1 cc per FPE, but 800 cc will certainly work, just a bit less efficiency is all, hardly noticeable.... For reference, a roundball of that caliber is 731 gr.... and a 1 caliber long cylinder is 1096 gr....
A 20mm bore is 0.787".... With full bore-size porting, running on 3000 psi in a 24" barrel, the theoretical maximum FPE using my spreadsheet is 1459 FPE, if you are using a bullet of 730 gr. (ie a roundball).... That means it would be challenging to reach 950 fps with a roundball in a 24" barrel.... With your barrel length, a piece of cake, providing you had a large enough plenum to keep the pressure near 3000 psi during the shot....
I can calculate other possible outcomes, at different pressures, and also give you an idea of the bullet weight required, or possible, for a given velocity.... but more information is required....
Bob
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Thanks Bob, that was quick. I have 4000cc tank that is the biggest plenum volume that I was thinking of using. It's a 300bar / 4500psi tank. And well bullet weight is not a problem as they can be turned in a lathe or a mold made pretty easily for the tooling size is no longer a problem so around 1300-1600grains maybe.
But at first I'll start with the 800cc to see how things work, mainly how to seal the chamber properly without O-rings flying out. Hafto use viton seals I think.
Marko
Edit, and for speed, around 1000fps, is nice, but I will try to push it as high as possible just for the fun of it and to see how much can be had with 20mm air cannon err gun. But for shooting around 1000fps.
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Sorry, I didn't see the 300 bar number.... Carrying on, using 4350 psi, my spreadsheet says a maximum SD of 0.244 to achieve 950 fps in a 24" barrel.... It predicts a maximum, with bore-sized porting, of 2116 FPE with a 24" barrel.... If you use a 36" barrel (leaving some for the inefficiencies that will occur in any build), that goes up to 3174 FPE, and the SD increases to 0.365, or 1582 gr being the heaviest you could push at 950 fps.... So if the plenum was large enough, you should be able to push a 100 gram (1543 gr.) bullet at about 950 fps using 4350 psi in your barrel.... The problem is, that you need a plenum of about 3000 cc to keep the pressure up....
If you use 80% porting, you are down to about 2500 FPE, ie a 1250 gr. bullet at 950 fps, using a 2500 cc plenum.... Other combination are possible, of course.... To reach 1000 fps, your bullet weight (SD) will have to decrease....
Bob
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Thanks again Bob. Those are some serious numbers, and very much attention will be put in to the frame stiffness, some serious forces are at play.
This will be my most difficult build in every aspect.
Marko
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Very interesting build, I am tagging along for the ride. 8)
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Very interesting build, I am tagging along for the ride. 8)
+1!!
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Just a quick idea of how plenum volume affect the pressure, and hence the velocity.... Your barrel is 1100mm = 43.3", so the volume is 21 CI.... If the plenum is 2500 cc, that is 152 CI.... If the pressure in the plenum is 300 bar (4350 psi), once you open the valve and the bullet reaches the muzzle, the air has expanded to occupy 152 + 21 = 173 CI of volume.... That will drop the pressure to (152/173) x 4350 = 3822 psi at the instant of pellet exit.... The smaller you make the plenum, the more the pressure drops....
Something else to think about.... If you use a dump valve, you will be using 152 CI x 300 bar = 45,600 CI of air per shot to produce just 2500 FPE, an efficiency of 0.055 FPE/CI.... If you close the valve just as the bullet leaves the muzzle, you get exactly the same power, but you only use 21 CI of air at 3822 psi, which works out to 5568 CI, or 0.45 FPE/CI.... If you close the valve when the bullet is half way down the barrel, you will lose about 30 fps (3%), but use half the air again, and the pressure remaining in the tank will be 4067 psi, so now the efficiency is up to 0.79 FPE/CI.... I give you these numbers to encourage you to used a conventional valve, rather than the extremely wasteful dump valve....
Bob
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Something to consider indeed, the trouble is opening the valve big enough for big power. I will definetly use air assisted valve, small pilot valve opening the main. But then the closing is a big question, will it close and how quick.
Valve seating on 20mm hafto be around 23mm and the force keeping it shut is over 1200kg!
Knocking that open with conventional hammer is out of the question.
Drawing and working different ideas for sealing the chamber and so on.
Marko
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Perhaps you can use a port reading barrel pressure, and close the valve after it drops to "zero" (ie when the pellet exits).... Even saving some of the air is better than nothing....
Bob
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One thing I have been thinkin is a gas piston like most semiautomatics use, barrel port around 2/3 way from chamber, and the pressure behind the bullet slams the valve shut before the bullet exits the muzzle.
Marko
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Good idea, if you can get it to function properly.... By the time the bullet is 2/3 of the way to the muzzle it has about 98% of the maximum possible FPE.... The time lag to close the valve might still have it open when the bullet exits....
Bob
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Some work done here and there, first part picture of tapping the breech for the madsen barrel. Thread is M30x1.5
(http://i6.aijaa.com/t/00988/14027779.t.jpg) (http://aijaa.com/d3JXHn)
Turning the madsen barrel.
(http://i4.aijaa.com/t/00047/14028250.t.jpg) (http://aijaa.com/JxOTgJ)
Marko
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I would think that a balanced valve would be the way to go, particularly if you want to use a dump valve.... Something configured like the Cothran Force Reduction valve, but simply vent the balance chamber in the head of the poppet to atmosphere.... The balance chamber would reduce the force required to open the valve, and once the poppet cracked off the seat the balancing force on the valve would actually slam it open.... It would stay there until the reservoir is empty, at which time a small spring could close it.... Something like this conceptual drawing....
(http://i378.photobucket.com/albums/oo221/rsterne/Parts%20for%20Sale/Balanced%20Valve%20for%2020mm_zpshvj32t19.jpg) (http://s378.photobucket.com/user/rsterne/media/Parts%20for%20Sale/Balanced%20Valve%20for%2020mm_zpshvj32t19.jpg.html)
The chamber on the right is vented to atmosphere.... there could be a small spring in there to close the valve after the pressure drops (or a much larger one to close it sooner?).... The opening force can be very small, as the air pressure only acts on the DIFFERENCE in area between the poppet seat and the balance chamber.... As soon as the valve cracks, the only significant force remaining is the balance piston, and that assists the opening of the valve.... The Cothran valve works on this principle (except the balance piston chamber is inside out, the piston is on the valve and the cylinder is part of the poppet), but the stem is drilled to vent that chamber into the exhaust port area, providing a closing force, and there is a "leaky check valve" inside the stem to slow down the airflow and prevent hammer bounce.... Neither are needed for a dump valve....
Bob
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Thanks Bob, that's a good concept aswell. But I'm going to use pilot valve to open stemless main valve.
There's going to be adjustable pressure feedback from tp to close the valve again.
Trial fitted the breech blank to the barrel. And the barrel is ready, man I hate turning barrels. Everything else is worth just material cost but barrels cost really something, try to find virgin AA barrel see what they cost. :o
That actual one was cheap but to replace it if you mess up on the lathe..
(http://i6.aijaa.com/t/00763/14028412.t.jpg) (http://aijaa.com/rbA66R)
Marko
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Please tell me you want to hunt with this. ;D
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It would be nice thing to see but unfortunately hunting is illegal when using airguns in Finland... :-[
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So then you are going to take it on safari?
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But I'm going to use pilot valve to open stemless main valve.
Marko
Something like this?
(http://i245.photobucket.com/albums/gg76/gippeto_album/High%20pressure%20co-ax/HPIM3743.jpg) (http://s245.photobucket.com/user/gippeto_album/media/High%20pressure%20co-ax/HPIM3743.jpg.html)
Al
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Yeah, something like that in the general idea. Adjustable opening and hopefully closing.
Hmm safari sounds interesting, but to drag everything over the world not so much. Lot of gear needed to shoot that big ag.
Marko
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Semi finished barrel and breech blank against one of our small lathes.
Man this thing is going to be big and heavy.
(http://i1.aijaa.com/t/00926/14028596.t.jpg) (http://aijaa.com/N5QhOo)
Marko
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Muahahhaaa! Just can't wait to see when it is ready...Timber!!!! :o
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What cal is this going to be?
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Didn't read the first page? It's 20mm Madsen auto cannon barrel I'm using.
Or to non metric people, it's .807 measured.
Marko
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20mm Anti-Aircraft barrel....
Bob
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Didn't read the first page? It's 20mm Madsen auto cannon barrel I'm using.
Or to non metric people, it's .807 measured.
Marko
Wow!! I some how missed that. That is huge!! I cannot wait till you get it finished!
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20mm Anti-Aircraft barrel....
Bob
Or Anti-Tank... Those are used in many configurations.
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Yes Bob, anti-aircraft, although for me it's just anti-air gun, or is going to be ;)
Timo found out what it was ment to go originally.
Got the barrel turned ready today, I do not like turning long pipes on a lathe.
It looks really big next to any of my other guns.
Breech is going to have claw type locks like pb chambers but at the rear of the bolt.
I really want that bolt to stay locked when fired, for it'll see same force as the bullet will.
More pics and progress as time permitting.
Marko
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2300 lb.f. at 4500 psi....need to design it for ~7000 lbs.... :o
Bob
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Got the breech and bolt almost done, only thing remains to do is the locking coupling and bolt handle.
Everything is very thick and heavy. Using six M5 12.9 bolts to mount the upper.
Pic of the breech.
(http://i1.aijaa.com/t/00576/14031880.t.jpg) (http://aijaa.com/oJAsdu)
Marko
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Tuning in to see this beast in action!
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Got the breech lock coupling done, it is locked with six lugs and one 8mm hardened steel pin. Just some frame components to be made and... :D
(http://i8.aijaa.com/t/00176/14036964.t.jpg) (http://aijaa.com/l6fV6U)
Marko
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Fascinating. I'm looking forward to more!
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Ahh, that is just big in diameter, nothing so interesting, sorry to spoil the party ;D
It is the valve I'm interested of. Nice to see how you get it work. Good luck anyway.
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Any progress on this build within the last month?
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Yeah, its about ready just need to find time to finish and assembly. Reservoir is still an undiseded what to use. I'll post pics when time permitting, some kitchen building is prioriezed higher in the list for some what reason ::)
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Come on Marko get back to it.
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Gotta keep those priorities in order Marko.
We need this project to come to fruition. Kitchens are over rated, besides. Theres always takeout. ;D
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Working on so much stuff but it's coming don't you worry. But I need support equipment and this is the priority now. (http://i8.aijaa.com/t/00578/14187252.t.jpg) (http://aijaa.com/Stb3yX)
Got a used coltri head cheap with busted fourth stage. So building a compressor around that.
And have broken back that have kept me out of the machine shop since January so that slows things down some.
Marko
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We're pulling for you, Marko !!!
Bob
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Thanks for the support Bob. Maybe I'll be back to the shop around August, if doc allows it. If not it'll be education to a new and lighter work. But it could be worse, I'm still standing and walking.
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Thanks for the support Bob. Maybe I'll be back to the shop around August, if doc allows it. If not it'll be education to a new and lighter work. But it could be worse, I'm still standing and walking.
Perhaps we should start a handicapped series so you can participate in the silhouette comps, we'll arrange a really wobbly chair for you to sit and shoot ;) Seriously though, get well soon.
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Sorry to hear of the back issues, I know them all too well.
Get better quick bro.
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Perhaps we should start a handicapped series so you can participate in the silhouette comps, we'll arrange a really wobbly chair for you to sit and shoot ;)
Well standing isn't problem at least for me sitting and laying down for longer period is...Not sure about what Marko's situation is...But sure IRC we have 3 fellows with intervertebral discs problem so price is guaranteed if only 3 take a part ;D
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Handicapped series my @@@, rkr you have seen me shoot just fine. It's just matter of pain management, and how much load I put on my back. And no reaching at all for anything heavier than a glass from the table.
But what comes to work, yeah I'm handicapped, can't sit too long or lift anything heavy or reach out and pick stuff up. I can work, for an hour or two but then I have to stop. That's the price of one hobby.
Anyways thanks guys.
Marko
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It's surprisingly hard to come along with these three handicapped competitors in matches. ;)
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It's surprisingly hard to come along with these three handicapped competitors in matches. ;)
A wobbly chair should give the rest of us some handicap :P
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Got something done today...
(http://i6.aijaa.com/t/00399/14190874.t.jpg) (http://aijaa.com/fzTntL)
(http://i4.aijaa.com/t/00806/14190875.t.jpg) (http://aijaa.com/ZPfjg9)
Marko
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20.55mm dropping at 1800gr / 117g
(http://i11.aijaa.com/t/00671/14191010.t.jpg) (http://aijaa.com/oGcVd4)
Marko
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Big chunk of lead, Marko!
Bob
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All thats missing now is the cannon that thing gets fired from.
Really nice looking slug Marko. How many you plan on making?
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Thanks guys, well we are going to shoot them today, from my friends gun. There where three of those AA-gun barrels and he has done a muzzle loader from one of them.
We cast 50 of these yesterday evening with Teemu just after I had finished the crude mold.
Only had yesterday from noon to make the mold so it's not perfect in any way.
Marko
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Barrel band machining
(http://i10.aijaa.com/t/00968/14284922.t.jpg) (http://aijaa.com/6iUI5T)
(http://i3.aijaa.com/t/00832/14284923.t.jpg) (http://aijaa.com/W6cCUi)
More to come in following week..
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Barrel band machining
(http://i10.aijaa.com/t/00968/14284922.t.jpg) (http://aijaa.com/6iUI5T)
(http://i3.aijaa.com/t/00832/14284923.t.jpg) (http://aijaa.com/W6cCUi)
More to come in following week..
LOOKING GOOD MARKO!
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Barrel band machining
(http://i10.aijaa.com/t/00968/14284922.t.jpg) (http://aijaa.com/6iUI5T)
(http://i3.aijaa.com/t/00832/14284923.t.jpg) (http://aijaa.com/W6cCUi)
More to come in following week..
Great your back onto this project......Be exciting what you can do with it when finished..............Will be watching Marko........As many projectiles i send down range, I would have to get a JOB to pay to FEED THAT RIFLE :o Good luck................Carl
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Thanks guys,
One more teaser for now, design phase of the valve block some time back.
(http://i4.aijaa.com/t/00441/14285616.t.jpg) (http://aijaa.com/Ug8SL1)
Marko
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First test of the 20mm valve on 30bar, just to see everything works as designed.
https://youtu.be/rDlODxAobG8 (https://youtu.be/rDlODxAobG8)
Marko
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30bar and still pretty scary ! awesome work.. just found this thread..
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KEWL!
Bob
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;D
Action
(http://i11.aijaa.com/t/00763/14288298.t.jpg) (http://aijaa.com/lrNxhG)
Marko
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that looks soo robust, im assuming this will weigh 25 lbs or so?
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Barrel, action and airtube tipping the scales at little over 10kg, don't know what that is in colonial units.
Marko
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wow, thats 22 lbs , AWESOME , its what we call a crew serve weapon in the US military (-;
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Thanks.
Some people has this obsession that all air guns that are worthwhile should be hunting capable, well you can hunt with this, just have to be man enough. ;)
I can shoulder it for a shot, but hafto aim quick. ;D
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Thanks.
Some people has this obsession that all air guns that are worthwhile should be hunting capable, well you can hunt with this, just have to be man enough. ;)
I can shoulder it for a shot, but hafto aim quick. ;D
DUH!!! That is a "MAN"S" gun Marko 8) Can't wait till you get 4000 psi driving a bullet....Good Stuff
Carl
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Thanks Carl, you and me both.
Can't wait to test it out, but now that I know the valve functions I need to hydro test the parts to see they are capable safely handle the intended 300bar pressure.
And I need to make another bullet mold, the 1800gr is a bit on the heavy side for testing.
I think I'll start with something light like 900-1200gr :o
Marko
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:o Well someone gonna burn fingers soon... ;D
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Maybe Teemu ;D
Second valve test @60bar, no projectile.
https://youtu.be/O3nNhKiHUZ8 (https://youtu.be/O3nNhKiHUZ8)
Marko
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;D
Action
(http://i11.aijaa.com/t/00763/14288298.t.jpg) (http://aijaa.com/lrNxhG)
Marko
Thats just simply awesome! I love the design, and even looks like the form drives function, eg that will be quite stabile while emitting a large projectile ;D
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until now , i never thought anyone would make a good looking mega big bore!
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Thanks guys,
And you are correct, the form is for the function, nothing more.
But somehow when you make something just to suite what you want it to do and not trying to make it pretty it just becomes good looking.
Marko
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Barrel, action and airtube tipping the scales at little over 10kg, don't know what that is in colonial units.
Marko
How about 3 liter CF bottle instead of the tube? It would give you enough air for two shots or something ;)
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How about you buy me one that's rated 300bar and is under 58mm diameter. ;)
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Looks very good. 8)
Would it be correct to assume that the hole in the side of valve block is an exhaust vent for pilot volume?
Al
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Correct for the time being, it will serve dual purpose later.
Marko
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More details, the business end of the rifle.
(http://i5.aijaa.com/t/00770/14288661.t.jpg) (http://aijaa.com/Phb081)
Marko
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i could have sworn there was a rule against posting porn (-'
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;D
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It was impressive to shoot one empty shot with 60 bars. I think it would of been even more impressive with bullet. 60 bars. I think it takes some daring to test with 300 bars. 8) Whoever will do it first time.
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Hydro next week and we'll see how it goes. Considering the mass it has it does kick with so low pressure.
First live shot is going to be interesting to say at least.
I think we are going to cast some rounds with Teemu and I'm going to turn some to get them a bit lighter.
Marko
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Ok a little update. Did hydro test yesterday and things went sideways.
First cycle 460bar ok
Second cycle 445bar and bang, valve blew out of the transfer port.
Well nothing dramatic but the blast shield I rigged up directed the spray in to my abb inverter that is going to go to my lathe. Well it got soaked. :(
So back to the valve, the design was changed sometime durring development and an o ring groove was cut.
Quick calculation and the burst pressure was down to ~4400psi whoops.
So a material is going to be changed over to peek and shallower groove.
Marko
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Ok a little update. Did hydro test yesterday and things went sideways.
First cycle 460bar ok
Second cycle 445bar and bang, valve blew out of the transfer port.
Well nothing dramatic but the blast shield I rigged up directed the spray in to my abb inverter that is going to go to my lathe. Well it got soaked. :(
So back to the valve, the design was changed sometime durring development and an o ring groove was cut.
Quick calculation and the burst pressure was down to ~4400psi whoops.
So a material is going to be changed over to peek and shallower groove.
Marko
Did you use PET-P/Ertalyte for the valve?
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Pom, should have been ok with 5mm wall but forgot to check when o-ring groove was added.
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I don't think so. POM would of been too soft anyway, soft and brittle. Funny how it is possible to be too soft and brittle at the same time with plastics. It is like Newtonian fluids, kind of.
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Perhaps with very large diameter valves at high pressure, a steel poppet and PEEK seat would be structurally more secure?.... Thanks for the heads-up. one more thing for Big Bore builders to remember.... ::) :o
Bob
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Well don't need to worry about it now do we ::)
Uit was within specs needed but looking at the notch test well it would have probably broken in use.
I need to think of doing alu valve with peek sealing surface or complete peek valve.
Just need to order some 20mm peek rod, for I'm out.
Marko
Edit: it was the primary slide valve that exploded Bob.
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First test with a projectile in the breech. Well O-rings leak on the bolt. And sabot was on the small caliber size. But anyhow around 120bar in the tank and 40 gram sabotet projectile around 207m/s about 630fpe.
(http://i8.aijaa.com/m/00719/14328407.jpg) (http://aijaa.com/rA9tub)
Marko
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Pretty good start Marko, looking forward to see how far you go with it. Very good design with a lot of potential. 8)
Al
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Thanks Al, now just need to make a smaller mold. I'm not going to start testing with 117gram bullets at first. It's something like 1600grain?
Maybe something small like 50-70 gram at first, and more sabots. Can't wait to open her up 300bar on air and when everything works switch to helium to make some serious power.
Marko
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Just shows when done right helium is not needed. So 630 fpe on less then 1800 psi.
Nice
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Just shows when done right helium is not needed. So 630 fpe on less then 1800 psi.
Nice
pretty hard to fathom , lol.
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Thanks Doug and Rob.
Now just needs the weather to cooperate and do more testing. It's raining subfreeze mist that freezes on contact. Not my kind of weather to test anything.
I'll start working on the mold next week and there are some sabots on the way so it'll be interesting when weather clears.
Marko
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Thought this was the rifle I saw on Mr Hollowpoint's video of the 20mm Rifle recently. That round looked more like an M203 round from back in the day..lol.
I think he may have shot that rifle with Helium but I'm not sure. I know the tanks were stacked :P Awesome looking work you got there.. very shmexy
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Thanks, It's not the same rifle, this is one of a kind. It's been in development for some time now.
Marko
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Hope this is still moving along, very interesting work!
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Yeah its moving along slowly, life got in the way. Compressor broke, car broke, mill spindle needs attention etc. ::)
Marko
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Got some kind of stock made. Not too comfortable tough.
180bar gives a nice push using sabott and 500gr light projectile.
Chrony didnt like to play ball so no idea on the speed.
(http://i5.aijaa.com/m/00071/14391544.jpg) (http://aijaa.com/HLK9lV)
(http://i3.aijaa.com/m/00844/14391545.jpg) (http://aijaa.com/Z7Ok3m)
Marko
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that looks absolutely awesome !
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Got some kind of stock made. Not too comfortable tough.
180bar gives a nice push using sabott and 500gr light projectile.
Chrony didnt like to play ball so no idea on the speed.
(http://i5.aijaa.com/m/00071/14391544.jpg) (http://aijaa.com/HLK9lV)
(http://i3.aijaa.com/m/00844/14391545.jpg) (http://aijaa.com/Z7Ok3m)
Marko
NICE...With my Tex at good power, I fold a kitchen towel on shoulder and The bruises are going away now.......Carl
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Thanks Rob, :D
Carl, I know hard to imagine getting bruised by an airgun, pcp guns dont have any recoil I have been told :o
My shoulder is already purpleish and blue from shooting steel butted M39 and the Savage .457 then the 20mm. Didnt feel any better shooting that with an solid aluminum stock.
Need to try the towel trick next, thanks.
Marko
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questioN,what holds the bolt forward when chambered??
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Six locking lugs on the bolt rear part and one 10mm locking pin on the bolt front.
There is a picture of the lugs at the beggining part of the thread.
Marko
Edit: reply #36 if I looked corret. The pin mentioned there has been chanced to 10mm
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Little update,
So dump valve started to feel dumb and I wanted to change that.
I have been testing a new design and it looks promising. 17mm port in the valve and I can open the valve with 100g hammer and with light spring at 100bar. So more hammer is needed and more spring.
Made 565fpe at 80bar, with 520gr saboted projectile. 20bar was used from the reservoir and valve cycles very fast.
More testing with more spring next. Then a heavier hammer.
Picture of the valve frame being machined.
(http://i5.aijaa.com/m/00532/14403396.jpg) (http://aijaa.com/D2xhod)
Marko
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looks great.."" Made 565fpe at 80bar"" that speaks volumes, basically making 565 fpe at co2 pressures.
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And more to follow, shot 423gr projectiles with 75.3gr sabots, so combined weight is 498.3gr that gives muzzle energy today starting with 1357J or 1001fpe on 150bar of AIR!
Working on tuning the valve to get to higher pressures.
Pictures of my chrono reading, and sadly after that it got hit with plastic sabot fragments and died.
But all in all a very rewarding and informational day.
(http://i5.aijaa.com/m/00361/14403565.jpg) (http://aijaa.com/QtxKMN)
(http://i3.aijaa.com/m/00157/14403566.jpg) (http://aijaa.com/LNV2dC)
Marko
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Well, I think you need some more sabots, will print them immediately when back home. Also think you need heavier bullets. Maybe Teemu could help on this? ;)
Sorry about your chrono, seems sabots are working ok.
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Yeah, out of sabots and bullets, already sent Teemu a message.
Killing the chrony just now when things got interesting is a major bummer.
Short video clip of one test shot.
https://youtu.be/IdPKYhwdOaA (https://youtu.be/IdPKYhwdOaA)
Marko
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Hammer at 100g, 17mm port, light spring AND 100 bar usually do not appear in the same sentence! Lol Thats fantastic, very nice work Marko!
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Yeah, out of sabots and bullets, already sent Teemu a message.
Killing the chrony just now when things got interesting is a major bummer.
Short video clip of one test shot.
https://youtu.be/IdPKYhwdOaA (https://youtu.be/IdPKYhwdOaA)
Marko
Real nice Marko..........Was the mirage up :o Little better SHOT PLACEMENT needed ::) Bummer on chrono. You will get all you expect, eventually............If it was easy everyone would be doing it.......
Carl
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Thanks guys,
Carl it was probably not the mirage, more like the alignment of stars I think. ;)
Well actually I thought that I hit the peak pressure where the valve opens, untill I saw this: (http://i10.aijaa.com/m/00101/14403809.jpg) (http://aijaa.com/qi0Glv)
Sabot being shot over the bullet, on higher pressure, the sabot bottom cant hold together on the accelerating the bullet on higher pressure and the bullet laggs behind. So that's why my chrono got blasted by plastic debris, the sabot exploded in the barrel.
New beefier sabots are being designed and hopefully we can find the peak pressure where the valve opens at.
And I found the partnumber for new lcd for the chrony. So that will get fixed when I'll get the screen.
This will be an very interesting summer!
Marko
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Nice to have friends that have a good supply of electronic components. On of my old friends came by yesterday and gave me a suitable lcd. :D
So chrony will be fixed pretty quick.
(http://i8.aijaa.com/m/00999/14404267.jpg) (http://aijaa.com/rCRMa4)
(http://i10.aijaa.com/m/00508/14404268.jpg) (http://aijaa.com/7oOdLb)
Marko
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Nice to have friends that have a good supply of electronic components. On of my old friends came by yesterday and gave me a suitable lcd. :D
So chrony will be fixed pretty quick.
(http://i8.aijaa.com/m/00999/14404267.jpg) (http://aijaa.com/rCRMa4)
(http://i10.aijaa.com/m/00508/14404268.jpg) (http://aijaa.com/7oOdLb)
Marko
Nice. Now try not to shoot it again?? I know, Sabot came apart :o
Carll
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You know Carl, I think I need to put a lexan shield angled in front of the chrony. Then maybe it'll stay in one piece if I dont hit it with the bullet. ;D
There are two kind of chronos out there, those that have been shot and those that are going to be shot.
How is your endeavors going Carl? Hope you don't get bored too soon, like reading about your shooting and all.
Marko
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You know Carl, I think I need to put a lexan shield angled in front of the chrony. Then maybe it'll stay in one piece if I dont hit it with the bullet. ;D
There are two kind of chronos out there, those that have been shot and those that are going to be shot.
How is your endeavors going Carl? Hope you don't get bored too soon, like reading about your shooting and all.
Marko
Lets hope this stays intact? I don't necessarily agree with the CHRONO Fable ::) I owned 5 Chronographs, shot thousands of rounds and NEVER hit one. With my airgun and .257's even shot through 2 at same time testing BC. at muzzle and 50 yds and didn't hit one...........I threw 2 CHRONY away after a year or so started reading 100 fps FASTER than reality.......Replaced and all good and 2nd did same thing.........Threw 2 away and still have 3. For POWDER I use the SWedisH Super Chrono and works ONLY supersonic on sound waves and is SWEET. No have never shot a Chronograph. I set it up hitting target aimed at then place CHRONO right in middle and never hit it........
Not quite ready to quit yet but soon.......All my .257 stuff have NOT FIRED ONCE since did the 1108 yds and one is all in pieces and have NO INTEREST in them at all.............Should sell 2 at least, and would but most people look for cheap &^^& to spend money on and wonder why it doesn't work well?? Most expensive stuff you can buy is CHEAP &^^&. Waste money on it and later upgrade and spend money to get quality and CHEAP STUFF A TOTAL WASTE. If I got close to value would sell some stuff.I would throw away before I give it to a cheapskate.
Little more with TEXAN yet and then???? Once I get bored I am done with things and move on... Several year later MAY get a spark???????? But 2 old now to worry about it.....
Good luck...Carl
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Its mostly a saying I hear that two kinds of chronos out there, didn't actually think I would shoot the chrony, but knowing that the sabots expand pretty rapidly it was a calculated risk. Timo made very good sabots and they work nice.
You are so right on the highend garbage, I have a one FX airguns rifle that should be on the better end of airguns and it's a complete &^^&.
Fortunately I didnt hafto pay anything for it, it was given to me for servicing and tuning one rifle.
It cost only couple hours of my time, and that is something I have some for not being still allowed to go to work.
Doc says that I need to find a lighter occupation that my back can handle.
So time is what I have but unfortunately it means no money. Go figure.
I can relate to the getting bored part pretty easily, have lots of hobby stuff laying in storage, mostly rc planes and helicopters. Could sell them but they are starting to look little interesting after all these years. :o
Marko
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Little ot, but its my thread anyways.
Chrony repair started, desoldered the old lcd and substituted it with a 2x20 row ic socket strips.
So if it goes bad for any reason I can just pull it out and replace.
Unfortunately found one of the lcd drivers to be cracked also so that needs replacing. Parts are on the way and hopefully will be here within next week.
Couple of pictures.
(http://i5.aijaa.com/m/00412/14406621.jpg) (http://aijaa.com/JYhGIq)
(http://i5.aijaa.com/m/00628/14406622.jpg) (http://aijaa.com/5ceA8D)
Marko
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One thing I found out trying to crony my 1" round ball gun was that I had to put my chronograph in the shade of my barn for it to function properly. Some weird shadow / reflection problem .
-
No problems with readings, did check with labradar. The radar doesn't like sabots, it gets confused what to follow.
Works good without sabots.
Marko
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While waiting for parts and Teemu being invalid. :P
I need to cast for the first time in my life.
(http://i1.aijaa.com/m/00349/14411609.jpg) (http://aijaa.com/4JDcB2)
(http://i5.aijaa.com/m/00922/14411610.jpg) (http://aijaa.com/nhHA7L)
Marko
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Continuing my monolog, and casting experiments, some light rounds for sabot use on the fury. 450gr .50 hp and some 620gr or something. Couple of 1600gr also.
(http://i8.aijaa.com/m/00788/14411701.jpg) (http://aijaa.com/LakuCB)
Marko
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Darn :-X I miss few competitions and some goog ol range time....well maybe I learn something of this....atleast I hope ;)
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I can't wait until you lose the sabot and start slinging some REAL lead !!!
Bob
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same as Bobs sentiment, this may very well be the first gun ive ever seen push 2000 fpe..
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Well I'm slowly working my way there guys, it already kicks pretty good and I'm shooting the light stuff still.
And at lower pressures.
First full power pull will be interesting. Thinking about muzzle brake, it would be nice and would definitely look cool 8)
Marko
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So the day is here that I have tested a solid lead projectile. Weighing around 116 gram or 1790gr give or take half a gram.
Results are some what puzzling and we need more testing for at the moment I cant believe the labradar readings.
And its not so low that I don't dare to post it, quite the opposite. So no numbers until we have more proof one way or another. Short vid of the third shot on air with bullets and not sabots.
All I can say that with 165bar it kicks pretty hard with that projectile. And around 60-65bar is used for the shot.
https://youtu.be/vIgISqLtDnY (https://youtu.be/vIgISqLtDnY)
More to come for sure!
Marko
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that is simply scary at that LOW pressure !!!!!!! incredible !
-
Clang! ;D
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It is scary, and I need a stronger back stop. Punched a ~30mm hole trough my old tractor bucket I found at my backyard when I bought the house.
Shoulder is a bit sore. :o
Marko
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It is scary, and I need a stronger back stop. Punched a ~30mm hole trough my old tractor bucket I found at my backyard when I bought the house.
Shoulder is a bit sore. :o
Marko
Marko, that thing will be really scary with 4500 psi pushing. Last 2 times out with Texan I use this and shoulder bruises have healed and soreness gone now. https://www.midwayusa.com/product/1002531259/past-super-mag-plus-recoil-pad-shield-ambidextrous (https://www.midwayusa.com/product/1002531259/past-super-mag-plus-recoil-pad-shield-ambidextrous)
Carl
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Let me guess.... with the 1790 gr. bullet at 165 bar you are over 700 fps and/or 2000 FPE.... With that pressure drop, your valve is still open when the bullet exits the muzzle....
Bob
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Well Bob you are in the same thousand with the labradar. I will confirm the numbers maybe tomorrow if it wont rain.
Marko
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Marko, I assume it's legal to own an anti-tank gun there...................................:)
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Well kind of, its registered as powerfull airgun in my firearms license. ;D
Marko
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Thanks Carl,
I need to check that recoil pad, and I really need to make a muzzle brake. ::)
Its borderline on being scary fun or just plain scary. I think 4500psi will be scary mostly.
Hmm thinking helium next, need a brave a foolish soul to risk life and limb volunteer to shoot it at 4500psi helium ;D
Marko
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If my numbers are low, then >1000 fps and >4000 FPE should be possible with the same bullet on 4500 psi Helium.... Methinks you are talking Elephant gun there.... :o
Bob
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Numbers are telling me weird things too but we must check and double check it again. But anyway, it seems possible. Not propable but possible. Where the heck you need helium?
-
Where the heck you need helium?
For that pink Elephant? ;D
-
Numbers are always fun, and doing math before building made me build it like a tank. I know it should hold at 4500psi, but still it's pretty scary thinking about shooting it that high.
Might be pull string type of deal the first time. ;)
Marko
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Well it didn't rain today. But no good news or numbers. Was setting up the radar and doing some test shots around 1250fpe with sabots, unfortunately blew the valve again. It was expected for I made it out of Pom.
Next will be out of pet-p and testing will continue next week at the range.
Marko
Edit: pulled some lead shrapnel from the bucket today, they do get pretty flatfen out hitting the plate i hung up there.
(http://i9.aijaa.com/m/00713/14412895.jpg) (http://aijaa.com/KQquK8)
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Now that it's in parts again, and I finally have the four jaw independant mounted.
Time to do some modifications, like 10mm more hammer stroke.
(http://i4.aijaa.com/m/00448/14413106.jpg) (http://aijaa.com/ebqAPF)
Marko
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New mold on the way...
(http://i6.aijaa.com/m/00447/14413870.jpg) (http://aijaa.com/on1APT)
Marko
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Hi Marko, This is really interesting technology you are developing with your really big bore! I am especially interested in your sabot design. Is this something you can share, as I am in need of some ideas for making some smaller sabots to solve a "lead free" hunting situation for a hunter in Japan. Any help would be imensely appreciated!!
Thank you so much!
John Hagan
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Multi mold ready, one cavity adjustable weight.
(http://i11.aijaa.com/m/00365/14414014.jpg) (http://aijaa.com/3M8k8F)
Sorry John, cant help you out. Sabots are made by one comrade and its his design, I'm just shooting them.
Marko
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looks awesome ! I assume you just dial in the length of the slug as needed ?
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Thanks Rob, yeah you are right, bullet nose in the mold is moveable so I can alter the weight by bullet length.
Marko
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The one on the left is for size comparison, .513 at 650gr and the bore rider on the right is slightly bigger.
(http://i9.aijaa.com/m/00228/14414229.jpg) (http://aijaa.com/1M7bhT)
Marko
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The one on the left is for size comparison, .513 at 650gr and the bore rider on the right is slightly bigger.
Marko
You really should have put a .177 pellet in that picture for proper size comparison ;)
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Ok as requested.177 .30 .513 and 20mm
(http://i11.aijaa.com/m/00196/14414390.jpg) (http://aijaa.com/vfC9oZ)
Marko
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It took me a while to see another .177 pellet. ;D
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haahaha, the 30 cal looks like a toy and thats the biggest caliber ive fired from an airgun LMBO
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Ok as requested.177 .30 .513 and 20mm
(http://i11.aijaa.com/m/00196/14414390.jpg) (http://aijaa.com/vfC9oZ)
Marko
Wow that's a BIG bullet!! You're doing a great job there Marko. Congratulations...
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Whoa, Dude, that's amazing! I've been skimming through your thread, and all I can saw is 'wow'!!!
Very impressive!! 8)
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haahaha, the 30 cal looks like a toy and thats the biggest caliber ive fired from an airgun LMBO
It was epic, there was one diablo on my workbench and I was like oh there's .177 on the table. No wait thats .30, then needed to take one .177 from the box and I was like whatta.. Soo tiny.
The size makes you kind of blind how big something is. I mostly shoot the .457 and not the smaller rounds.
Marko
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Thanks Jeremy, it's been an interesting build for sure, and now its at it's most interesting part, testing has finally started.
And thanks to you milady Chickie for skimming through my thread. Glad you liked it. :D
Marko
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Did couple of bullets more, 25 smaller and 20 bigger plus two extra to test how big is the biggest from the mold. Total amount of lead spent 5.8kg
107gram 140gram and 157gram / 2422grain :o
(http://i7.aijaa.com/m/00039/14414810.jpg) (http://aijaa.com/ZgLfri)
(http://i1.aijaa.com/m/00399/14414811.jpg) (http://aijaa.com/xUArln)
Marko
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So numbers and sore shoulder :o
250bar and 140 gram bullet delivers 2275fpe on AIR! ;D
Previous numbers we got with lower pressures where echoes and we weren't sure so they remaint unpublished.
Pictures and videos will follow later this week!
I'm pretty happy with these numbers for today.
Marko
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that's incredible , I think the highest numbers ive seen before this were 1700 fpe or so on helium !
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Niiiiice!!!! 8)
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So just under 700 fps.... NICE!....
Bob
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And some video of one shot.
https://youtu.be/MR3HX5zOMEQ (https://youtu.be/MR3HX5zOMEQ)
We will continue tomorrow, have one bigger bullet to test and some more pressure.
Marko
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And some video of one shot.
https://youtu.be/MR3HX5zOMEQ (https://youtu.be/MR3HX5zOMEQ)
We will continue tomorrow, have one bigger bullet to test and some more pressure.
Marko
RECOIL MUCH ::) ::) ::) That is insane Marko............How many psi per shot???? The jump at muzzle will make it really difficult to repeat impact point I am thinking. What a monster you have created sir!!! Entertaining stuff.....waiting for MORE MOVIES 8) 8)
Carli
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Thanks Carl,
Well it is VERY demanding to the shooter to get a follow up shot I cen tell you that. :o
It really needs a muzzle brake, you can ask Timo how much it does kick when not fully prepared of it.
He was waiting for the kick but still it got him off guard. I can post the video if Timo approves it.
Its been a long and bruising day so off to sleep and we will continue in the morning.
Marko
Edit, forgot to reply to the psi question, around 55bar /78psi per shot. Had to edit again, calc error dividing in my head. ::)
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Jeez, I'd really like to join you guys on saturday to see some action and to shoot myself but unfortunately it's a no go due to family crisis. Have fun and post more videos.
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And some video of one shot.
https://youtu.be/MR3HX5zOMEQ (https://youtu.be/MR3HX5zOMEQ)
We will continue tomorrow, have one bigger bullet to test and some more pressure.
Marko
Whoa! 8)
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pure cannon , amazing !
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Thanks people,
Small update, 270bar 158gram bullet 2447FPE on AIR!
I will post videos later today in the evening. This will be it for now, valve lock past 270bar so we have another 30bar left.
I'm very happy with this!
Marko
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Some more video, had very much fun today and will probably pay for it tomorrow. Neck is a bit sore and shoulder hurts some.
Did use the towel to reduce the recoil today, so thanks for the tip Carl.
Did made video on the valvelock, it was pretty epic, was like here goes nothing and small pop. :o
May or may not post it.
https://youtu.be/nhspIvKxSiY (https://youtu.be/nhspIvKxSiY)
Marko
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Impressive, Marko.... Better your shoulder than mine!.... *LOL*....
Bob
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Some more video, had very much fun today and will probably pay for it tomorrow. Neck is a bit sore and shoulder hurts some.
Did use the towel to reduce the recoil today, so thanks for the tip Carl.
Did made video on the valvelock, it was pretty epic, was like here goes nothing and small pop. :o
May or may not post it.
https://youtu.be/nhspIvKxSiY (https://youtu.be/nhspIvKxSiY)
Marko
Great stuff Marko........Killer recoil......If you plan to shoot that much, brake as you know it needs, and add weight to absorb some energy besides the shoulder........Your welcome on towel but yours kicks 3 times harder than mine, and last 2 times i dug out the Past Magnum Recoil Pad and shoulder is fine......Besides it has a strap and hangs in place as towel falls off at each movement ;) ADDED WEIGHT will ease bench shooting.......
I shot a 50 BMG in Competition for 10 years and recoil was BIG. 800 grains at 2800 fps is 13,900 fpe BUT Light gun limit was 32# and heavy gun up to 50#, so absorbed a LOT of the recoil. Have had recoil CRACK my neck before and need a Chiropractor :o
Good stuff and thanks for the video......I have passed it on to my shooting friends.......................Carl
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Recoil felt in the gun is in the ratio of gun weight to bullet weight, and of course related to FPE level.... 800 gr. bullet is 0.114 lbs, so a 32 lb. gun is 280 times as heavy as the bullet, and a 50 lb. gun is 440 times the bullet weight.... Marco is shooting a bullet that weighs 0.35 lbs.... I don't know what his gun weighs, but at 2447 FPE, compared to 13,900 FPE for the .50 BMG, with a bullet that is just over 3 times as heavy, it should have to weigh about 17 lbs. (about 50 times the bullet weight) to have the same felt recoil as a 32 lb. gun shooting the .50 BMG.... if I got my numbers right.... ::)
Bob
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Bob you are forgetting the thrust effect from the muzzle that makes most of the recoil in big power airguns.
Not to diminish the fact that 50bmg does kick pretty good. Dont know how it compares to 500ne but it has a good kick aswell.
I know I can reduce the felt recoil by reducing valve dwell, but its not so easy to do that. I have 17mm valve feeding the barrel size ports, and every ounce energy we can get from that air was the goal.
So recoil, lots of it, if you think a 12gauge kicks hard with slugs, think again. ;D
Its not the most comfortable gun to shoot but definitely exiting one to shoot.
And now some data, 140g projectile V0 212m/s and V100 208m/s Those bulletts are retaining energy very well.
Perfect round holes on paper, and doesn't need too much holdover to get to 300m
Marko
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True, there is a lot of air mass exiting the muzzle as well.... proportionately more than the mass of burnt powder in a .50 cal I would think.... although at a lower velocity....
Bob
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This certainly has the power for long range shooting. Any ideas how accurate this gun is, or is that even important?
Are you planning to put sights on there? I think this would be one of the faster ways to get eye makeup ;D
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So far this is the biggest big bore I have heard of, besides a cannon that is. Great to see a project work out as well as this one has for you. It would be interesting to see what kind of grouping could be achieved at 100 and even 300 meters. And you are only at 250 bar? If you take this all the way to 310 that would be completely and utterly terrifying. I don't imagine it would even have an efficiency rating, still when going for raw power, who cares.
Thank you for sharing your project with us.
Dave
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All I can say is :o ... Unreal... and I know it is real ;D And if that hits well at 100M You need to get Your own patches for paper target :P
Good luck on silhouette competition fellows . I wish I was there...
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Thanks for all the nice comments people.
Its as accurate as you can imagine sighting over the reciver, I can hit a fryingpan at 50m and paper target at 100m. It hit 3 rounds within one square meter at 300m without sights. So I think it will be accurate when I'll put a scope on it.
Going to be a long eye relief model for sure! 8)
Marko
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Two more videos, first one shootning a fryingpan and second is a friend shooting the gun for the first time.
https://youtu.be/wU-Kr0iCTRU (https://youtu.be/wU-Kr0iCTRU)
https://youtu.be/x633cyfwsUg (https://youtu.be/x633cyfwsUg)
Marko
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Ok, it is tested, now we need to see what helium does with that barrel surface area. 8)
We actually had 2 12l tanks of helium but no one with enough of courage to test on it. ;D
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Total recoil should be about the same, no?.... Reduced gas mass by using Helium puts that extra energy into the bullet instead, but the total FPE output (gas plus bullet) should remain roughly the same, at the same pressure.... Maybe a slight increase from better flow with the smaller atoms, but that should be relatively minor....
Bob
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any predictions for helium?? my guess is 4000 fpe !
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Reduced gas mass should help as I think that recoil is pretty much due to massive air flow. Hope so. It still is difficult to find a voluntary to test. And I'm slighty disappointed if this monster can't acchieve 4000 fpe with it.
Maybe we start with lower pressure first, I think.
-
I think Newtons Third Law of Motion will apply "Newton's Third Law of Motion. It states, “For every action, there is an equal and opposite reaction.” Forces always occur in pairs; when one body pushes against another, the second body pushes back just as hard."
Going further as you guys are talking--"According to the law, the force exerted by object 1 upon object 2 is equal in magnitude and opposite in direction to the force exerted by object 2 upon object 1."
Not being a PHD in Physics, I would think accelerating that 2500 gr bullet FASTER by whatever means will also get MORE RECOIL. This will be true as in my years of powder reloading, lighter accelerated loads=mild recoil and the faster even a light bullet is accelerated, the MORE FELT RECOIL, ALWAYS. No matter what size bullet you are accelerating. Can't change the laws of Physics.
In ENGINEERING there are no free lunches.....Get something here, usually give up something elsewhere. In the helium discussion, probably get more fps and fpe but will get correspondingly MORE RECOIL.
Helium won't double the power on that big bore but will be easily 50% more of EVERYTHING. MARKO, you will FEEL THE LOVE when you touch that puppy off ::) ::) ::)
Carl
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Carl, there is a significant part of the recoil due to accelerating the air mass out the muzzle.... Helium is 1/7th the density of air, so there will be only 1/7th the mass being accelerated.... That additional available energy can be used to accelerate the bullet, that is EXACTLY where the extra velocity comes from when you use Helium.... Yes, the bullet will end up going faster, and there will be more recoil from that.... but there will be only 1/7th the recoil from accelerating Helium instead of air.... It should, relatively speaking, be a wash....
Assuming my numbers for the gun are correct....
Reservoir = 800 cc
Barrel volume = 2^2 x PI/4 x 110 = 345 cc
Starting pressure = 265 bar
Muzzle pressure = 265 x 800 / (800+345) = 185 bar
Air density at 185 bar = 216 kg/m^3 = 0.216 g/cc
Mass of air in the barrel = 345 x 0.216 = 74.5 grams = 1150 grains
For Helium, density at 185 bar = 28 kg/m^3 = 0.028 g/cc
Mass of Helium in the barrel = 345 x 0.028 = 9.66 grams = 149 grains
Therefore, using Helium instead of air, there is over 1000 grains less mass being accelerated out the barrel.... assuming an 80 bar pressure drop during the shot.... If the pressure drop in the reservoir is less, then all numbers are reduced by the same ratios.... If, on the other hand, the valve dumps and empties the reservoir, the entire air mass of 234 grams (3617 grains) would be exhausted through the muzzle, causing more recoil than the bullet itself.... :o
Bob
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Carl, there is a significant part of the recoil due to accelerating the air mass out the muzzle.... Helium is 1/7th the density of air, so there will be only 1/7th the mass being accelerated.... That additional available energy can be used to accelerate the bullet, that is EXACTLY where the extra velocity comes from when you use Helium.... Yes, the bullet will end up going faster, and there will be more recoil from that.... but there will be only 1/7th the recoil from accelerating Helium instead of air.... It should, relatively speaking, be a wash....
Assuming my numbers for the gun are correct....
Reservoir = 800 cc
Barrel volume = 2^2 x PI/4 x 110 = 345 cc
Starting pressure = 265 bar
Muzzle pressure = 265 x 800 / (800+345) = 185 bar
Air density at 185 bar = 216 kg/m^3 = 0.216 g/cc
Mass of air in the barrel = 345 x 0.216 = 74.5 grams = 1150 grains
For Helium, density at 185 bar = 28 kg/m^3 = 0.028 g/cc
Mass of Helium in the barrel = 345 x 0.028 = 9.66 grams = 149 grains
Therefore, using Helium instead of air, there is over 1000 grains less mass being accelerated out the barrel.... assuming an 80 bar pressure drop during the shot.... If the pressure drop in the reservoir is less, then all numbers are reduced by the same ratios.... If, on the other hand, the valve dumps and empties the reservoir, the entire air mass of 234 grams (3617 grains) would be exhausted through the muzzle, causing more recoil than the bullet itself.... :o
Bob
Well when Marko touches it off with Helium, he will let us know how it feels :o
Carl
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Put the muzzle brake :D
https://youtu.be/gPhSxDwhTIA?t=87
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With my previous experience shooting bigbores on helium, the recoil will be worse.
The gas speed is so much faster, it will dump way more helium than air.
I have one week till next track session to make some modifications to the rifle and manufacture a brake for it.
Then we will know how it will do on helium.
The gun can take extra punishment that helium puts on it.
Lets find out where the limit is for now, someone will no doubt push further one day.
Marko
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I think Newtons Third Law of Motion will apply "Newton's Third Law of Motion. It states, “For every action, there is an equal and opposite reaction.” Forces always occur in pairs; when one body pushes against another, the second body pushes back just as hard."
Going further as you guys are talking--"According to the law, the force exerted by object 1 upon object 2 is equal in magnitude and opposite in direction to the force exerted by object 2 upon object 1."
Not being a PHD in Physics, I would think accelerating that 2500 gr bullet FASTER by whatever means will also get MORE RECOIL. This will be true as in my years of powder reloading, lighter accelerated loads=mild recoil and the faster even a light bullet is accelerated, the MORE FELT RECOIL, ALWAYS. No matter what size bullet you are accelerating. Can't change the laws of Physics.
In ENGINEERING there are no free lunches.....Get something here, usually give up something elsewhere. In the helium discussion, probably get more fps and fpe but will get correspondingly MORE RECOIL.
Helium won't double the power on that big bore but will be easily 50% more of EVERYTHING. MARKO, you will FEEL THE LOVE when you touch that puppy off ::) ::) ::)
Carl
I'm with Carl on this one!
My past experience with helium, and with reloading is telling me the exact same thing.
Its going to be and epic shot no matter what.
I hope there is enough time to mount a scope on the gun, because power is one goal, but I want see how she groups.
Theory and practice, there is one way to find out, touching it off and seeing what happens.
I'll post more videos later.
Marko
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Also my experiance tells me about more recoil on helium. If Marko have time enough to make muzzle brake, that will cut off about half of it at best and that would be very welcome effect with this gun. It is heavy as *(&^ but still kicks like a mule.
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I want to mention about my former experiences with one .457 DAQ rifle, it had surprising recoil for that caliber airgun. Few guys nearly joined to panda-club with it and it shaked all the srews loose all the time. Literally only trigger guard was tight when we noticed it. :D We took a high speed video and found out there was at least three pulses of air going after bullet. I made some modification, much lighter hammer and some spring adjustment and also glued all the screws and barrell. Power did not reduce but recoil and air consumption decreased remarkably.
This is something that is almost impossible or at least very difficult and time consuming to do with 20mm as valve diameter is so large. It must open and it is actually not that important if it consumes air. Power is the main goal and it certainly has it.
And now that I wrote this it cleared in my mind, we must do a slowmo video to see what really happens. In next session for sure. Maybe not for changes but just to examination. Air(gas) flow from the muzzle acts like rocket nozzle creating a lot of thrust. Therefor muzzle brake can cut it remarkably. Of course bullet acceleration will create similar counter force as physics tells us but in this puppy there is certainly something more than that.
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Your experience with your DAQ is similar to mine with my .308 Exile.... The gun was so oversprung that by shortening the hammer spring I was able to save 60% of the air without any velocity loss.... I went from a 3 shot "cliff" shot string to a 6 shot shallow bell curve, where my 5th shot was faster than the 2nd shot was stock.... The recoil and noise were also dramatically reduced.... Note I mentioned above that if the gun dumped all the air, there would be more recoil from the air than from the bullet....
Bob
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All good and fun, guys.
Video from the track, one of our fellow shooters trying the 20mm out. He did not see anybody else shoot it before and was not fully prepared for the recoil.
https://youtu.be/OrBC-w-5yCs (https://youtu.be/OrBC-w-5yCs)
Marko
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.. The recoil and noise were also dramatically reduced.... Note I mentioned above that if the gun dumped all the air, there would be more recoil from the air than from the bullet....
Bob
It would be nice to tune the valve, but its like all or nothing type of deal. It makes a puff or bang but nothing in between. But I'm immensely glad I didnt try it out with the dump valve more than valve tests at 60-80bar.
We shall see what comes of it after the brake is installed, gun like this should have a hefty kick to be manly enough. ;)
It looks like monster so it should act like one.
Marko
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All good and fun, guys.
Video from the track, one of our fellow shooters trying the 20mm out. He did not see anybody else shoot it before and was not fully prepared for the recoil.
https://youtu.be/OrBC-w-5yCs (https://youtu.be/OrBC-w-5yCs)
Marko
I think that does not need translation... ;D ;D
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With my previous experience shooting bigbores on helium, the recoil will be worse.
The gas speed is so much faster, it will dump way more helium than air.
I have one week till next track session to make some modifications to the rifle and manufacture a brake for it.
Then we will know how it will do on helium.
The gun can take extra punishment that helium puts on it.
Lets find out where the limit is for now, someone will no doubt push further one day.
Marko
What is the TRACK SESSION (Season) Racetrack???? Curious??
Carl
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Hehhe me and my english, range session Carl.
Was not fully awake when I wrote that.
In Finnish "rata" is short of "ampumarata"= Shooting range and the "rata" part is also track as in race track or railway track, etc.
So there you have it, and good morning its 6 o'clock in the morning here in Finland.
Marko
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Hehhe me and my english, range session Carl.
Was not fully awake when I wrote that.
In Finnish "rata" is short of "ampumarata"= Shooting range and the "rata" part is also track as in race track or railway track, etc.
So there you have it, and good morning its 6 o'clock in the morning here in Finland.
Marko
Thanks for clearing that up for me...........Let's just say your English is a Tad Better than my FINNISH ::) I can only speak 2 languages, Vulgar and Profane ;)
Good Day to you and about ready for bed here ..............Carl
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Ok, now the fun and fine tuning begins, have gotten the brake roughed out and will be milling the ports today.
Will also make small adjustments to the ports of the rifle, polishing and contouring everything.
Bigger hammer is on the to do list, I want that valve open at 300bar!
Got all the chrony parts and got the pcb back together, added couple of buttons and eproms to the board and it now recognizes itself as beta master.
Pic of the progress on the brake and chrony
(http://i8.aijaa.com/m/00835/14418153.jpg) (http://aijaa.com/Bortfw)
(http://i1.aijaa.com/m/00106/14418154.jpg) (http://aijaa.com/R3ELGC)
Marko
-
Remember take a helmet,toothcover, and pair of new underpants ;D
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MARKO, Now that is a BRAKE ::) Size of a SOUP CAN :o But ports to direct the massive volume of gasses, to help SLOW recoil will be big difference..............Can't wait..................Thanks for all the updates.........
Carl
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No problem Carl, thanks for watching.
Roughing out ports in the mill, still not sure should I make ports on two or four sides. Need to see how it looks with ports on two sides first.
(http://i10.aijaa.com/m/00519/14418814.jpg) (http://aijaa.com/ctIvmy)
Marko
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Brake trial fitted to the barrel.
Looks the part, hope it does the job. 8)
(http://i11.aijaa.com/m/00841/14419122.jpg) (http://aijaa.com/jyKz6r)
(http://i3.aijaa.com/m/00016/14419123.jpg) (http://aijaa.com/LQq4Zs)
Marko
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looking bad--s !
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Thanks Rob,
Form follows function and it turned up quite nice.
Marko
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No problem Carl, thanks for watching.
Roughing out ports in the mill, still not sure should I make ports on two or four sides. Need to see how it looks with ports on two sides first.
(http://i10.aijaa.com/m/00519/14418814.jpg) (http://aijaa.com/ctIvmy)
Marko
DO NOT put ports on 4 sides...........I suggest smaller HOLES on TOP to HELP DIRECT flow UP and help with muzzle FLIP!! Suggestion ONLY but I would NOT VENT on bottom as muzzle jumps plenty already...........Just my thoughts............It is your brake
Carl
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Carl, your succestion is reasonable and maybe Marko could consider couple small holes, like 8-10 mm's but I must say it didn't actually jump. Recoil was very good what comes to direction but not quantity. Little bit less for me would be enough to feel I am shooting. ;D But it is easy to do and does not any harm in any way, so good idea.
-
Thanks for the input Carl,
I'll try it as is and see how it works, it's easier to add more holes afterwards than plug existing ones.
Marko
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We can do it on range if we think it is necessary.
-
I think a suppressor would do a great job dampening recoil, but then again it would have to be something big and sturdy. Do you have any questimations concerning muzzle pressure or expelled air volume?
-
Thanks for the input Carl,
I'll try it as is and see how it works, it's easier to add more holes afterwards than plug existing ones.
Marko
This is what i use on Texan........ https://www.jprifles.com/buy.php?item=JPTRE-5.58S.925 (https://www.jprifles.com/buy.php?item=JPTRE-5.58S.925)
Carl
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I think a suppressor would do a great job dampening recoil, but then again it would have to be something big and sturdy. Do you have any questimations concerning muzzle pressure or expelled air volume?
It would hafto be a quite large can I recon. Guesstimating around 180-220bar and 30000cc could be wrong.
I see you are in Finland, how about joining one of our competitions one day? You can find us at Sihry forum.
Marko
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Marko, if you give me the reservoir pressure before and after a shot I can calculate the muzzle pressure and air volume released during the shot.... 800 cc reservoir and 110 cm barrel, right?....
Bob
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I think a suppressor would do a great job dampening recoil, but then again it would have to be something big and sturdy. Do you have any questimations concerning muzzle pressure or expelled air volume?
It would hafto be a quite large can I recon. Guesstimating around 180-220bar and 30000cc could be wrong.
I see you are in Finland, how about joining one of our competitions one day? You can find us at Sihry forum.
Marko
It would have to be a huge can. I have 10" long can made from 2" pipe that's barely adequate for 300 fpe and has actually some challenges holding internals together. If you extrapolate that to Marko's power level it would not be practical anymore.
-
Suppressor is not necessary. I think no one considers this "backyard friendly" anyway. ;D
-
I didn't even think that the suppressor would make this gun silent (they rarely do), it was just interesting to think how large the can would have to be to get any notable effect on recoil or sound.
-
Marko, if you give me the reservoir pressure before and after a shot I can calculate the muzzle pressure and air volume released during the shot.... 800 cc reservoir and 110 cm barrel, right?....
Bob
Well you got the barrel correct but the reservoir is about 450cc.
Last i checked it took around 65-80bar for shot, max pressure we got the valve open was at 265-270bar
Marko
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I didn't even think that the suppressor would make this gun silent (they rarely do), it was just interesting to think how large the can would have to be to get any notable effect on recoil or sound.
I've used the can I mentioned at 150 fpe level and it's roughly equal to HW can at 30 fpe level.
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OK, so with a 450 cc reservoir, a 265 bar fill, and 200 bar after the shot, the volume of air used is (450/16.4) x (265-200) = 27.4 CI x 65 bar = 1784 CI.... For a shot of 2447 FPE, that is an efficiency of (2447/1784) = 1.37 FPE/CI.... which is astoundingly good....
If for the same shot you used 80 bar, then we have 27.4 x 80 = 2192 CI, and the efficiency would be (2447/2192) = 1.12 FPE/CI.... If we use a few reasonable assumptions, Lloyd's Internal Ballistics Spreadsheet models the results as follows....
With a 65 bar drop the air used is 450 x 65 = 29,250 cc.... and the residual muzzle pressure with a 43" barrel should be about 840 psi.... approx. 70% efficiency, with the valve closing when the bullet is about 18" from the breech, with a valve dwell of 5.1 mSec....
With an 80 bar drop the air used is 450 x 80 = 36,000 cc.... and the residual muzzle pressure with a 43" barrel should be about 1170 psi.... approx. 64% efficiency, with the valve closing when the bullet is about 23" from the breech, with a valve dwell of 6.2mSec....
Substituting Helium, and only compensating for the mass difference, but using the same valve dwells, it predicts about 2800-2850 FPE.... What it can't calculate is if using Helium will change the valve dwell compared to air, or if there is an effect from the smaller molecules, this is solely based on the reduced mass of Helium compared to air....
Bob
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Marko,
I must say this is a fascinating project, I'm very impressed with your progress and your ability to get it done! The most amusing part for me is the barrel has a larger OD than the the airtube LOL; the most interesting part for me is the performance analysis because this baby is so far outside the box!
Well done sir!
Tom
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Thanks Bob for doing the math, we will have more data on helium next week Monday or Tuesday.
Well Tom, its been a long time comming and now that I made the new valve substituting the dumb valve.
It started to get interesting again and I can't really stop working on it to be honest.
I want to see what can be had with this platform on air and then the absolute maximum on helium.
I'll cast more ammo this week and will skip all the light stuff, well if you can call 108 gram light ::)
140-158 grams, or if I can extend the mold just a tiny bit and get to around 170 gram.
The 140g has a calculated g1 bc around .711 measured from 0-100m the holdover was a lot less than I expected for 300m and shot over the berm in to the trees. Did make lot of noice in the forest.
Marko
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Long hours in the shop, couple of picatiny rails done and extra hammer weight, plus remote housing for the chrony display and electronics.
(http://i4.aijaa.com/m/00584/14420011.jpg) (http://aijaa.com/tyQ8C5)
(http://i2.aijaa.com/m/00600/14420012.jpg) (http://aijaa.com/gTU1l9)
(http://i10.aijaa.com/m/00874/14420013.jpg) (http://aijaa.com/6GjKQO)
(http://i7.aijaa.com/m/00791/14420014.jpg) (http://aijaa.com/UVv1Er)
Marko
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Next week will going to be very interesting.
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Yes indeed. Lets see what are the final numbers on air. I'm really hoping the extra 45g of hammer mass will help opening the valve at 300bar.
I will cast some bullets tomorrow after I have turned a barrel for Eve.
Marko
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Just freakin wow...
Lotta luv in that project :)
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Thanks Tom.
I have had some spare time so I try to make the best of it.
Marko
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Marko, I love the way you executed your receiver by taking the design well beyond the typical tube gun :)
Tom
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Thank you Tom,
Something like that comming from a manufacturer of one of the finest american rifles. It means a lot. :D
Its the first thing I really was thinking about a lot, the forces are so great that I wanted the extra safety of 6 locking lugs.
Its built more likea powder reciver than an airgun really. There is no separate transfer port between the lower and reciver, only a 2mm thick alu sealing ring.
Marko
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Getting ready for another range session, casting bullets from light(ish) 146 to heavy 174gram. Ammo starting to look like mortars. ;D
Did make another barrel for a the good old trusty .357 this time in .311 and my girl Eve can test it out.
What a better way of ending the week, reloading brass and casting ammo to spend it again next week 8)
(http://i5.aijaa.com/m/00760/14421332.jpg) (http://aijaa.com/mUMpOX)
Marko
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And some perspective on the size of the rifle, found a suitable scope that doesn't look too small.
It looks pretty big, about as long as I am. ;D
(http://i9.aijaa.com/m/00795/14422481.jpg) (http://aijaa.com/mGawjW)
Marko
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HOLY COW , its about double the size I imagined, unless of course you are 3 feet tall 8)
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The barrel is 1.1 meters long so adding the reciver and stock it became pretty darn long.
But it's built purely for fun. Its not going to be a hunting rig of any sorts.
Marko
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Wow...now that's a gun! Excellent build Marko.
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Love that shot, Marko.... really lets us appreciate how BIG this build is....
Bob
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Holy Cow...I had no idea of the size of that thing from the other pics! That's awesome!
Mike
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Suksethan tuo vielä tarvii :D
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And some perspective on the size of the rifle, found a suitable scope that doesn't look too small.
It looks pretty big, about as long as I am. ;D
(http://i9.aijaa.com/m/00795/14422481.jpg) (http://aijaa.com/mGawjW)
Marko
Thanks Marko for the PERSPECTIVE PHOTO............WOW is about all I can say............Great Work.
Carl
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;D pole vaulter
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Thanks for all the nice comments. :D
I was looking at the Anzio 20mm years back when I started this project and was thinking that it was a monster of a rifle, long as heck.
It looked BIG compared to the shooter and I kind of liked that overkill look.
So here we are and I have my own representation of that in airgun.
Today is the day we will unleash her on helium so stay tuned.
Marko
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Now all you need is a motorized cart to get it back and forth to the firing line! Just amazing!
pv
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Now all you need is a motorized cart to get it back and forth to the firing line! Just amazing!
pv
(http://image.superstreetonline.com/f/37148776+w640+h427+q80+re0+cr1/eurp-1203-01%2btop-gear-mobility-scooter%2bcover.jpg)
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So it seems that the planets didnt align too good for me.
First shot with air to setup Labradar and the valve blew. Well I thought its a no biggie I have a spare.
But the heavier hammer broke the valve gage that hold the auxiliary piston so thats that.
Back to the lathe tomorrow and back to the range on Thursday I hope.
Valve gage will be made out of crmo this time.
Marko
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Sorry to hear about the setback.
-
Still blowin' my mind, wow... :o
Y'all are doing some awesome stuff, but please, please, be careful, o-m-g!!!
Otherwise, carry on!! :D
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Careful is my middle name, milady. ;D
Calculated some forces and whoopsie I had made small error. Change of material and we will go again
Lathe will start turning first thing in the morning, after coffee that is.
High tensile steel will substitute the aluminum on the valve cage.
And peek for the valve instead of pet-p.
Marko
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I think I really get what you mean, nothing like a good cup of coffee in the early morning hours before the chips start emerging, but it is only fun when making something for yourself, and one should at least think that he knows what he is doing ;D.
I assume you are using something like Imatra MoC 210 M or even better MoCN 315 M. Is there a photo of the part in question, I'm very interested to see other peoples designs.
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"If you can't make it, you don't want it."
Lovely signature line, Finn, I like it!!
I am a big fan of the power of intention.
:-) chickie
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I think I really get what you mean, nothing like a good cup of coffee in the early morning hours before the chips start emerging, but it is only fun when making something for yourself, and one should at least think that he knows what he is doing ;D.
I assume you are using something like Imatra MoC 210 M or even better MoCN 315 M. Is there a photo of the part in question, I'm very interested to see other peoples designs.
Well I'm a cnc machinist, so I should know what I'm doing. ;)
Material of choice this time is 42crmo4 or as in America 4140H is the equivalent type.
As for design pictures, well its a prototype and I'm not quite ready show it to the world.
Did take look at your rifle build thread, very nice looking rifle, elegand and purposeful desing.
Marko
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Marko, is 1144 available ? Great machinability compared to chrome moly and has excellent strength and hadness without the need for heat treatment
Tom
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Yeah propably, but this is what I got at hand at home. So this will hafto do.
The 42 is a pain to machine for sure, atleast on my smallish lathe.
Marko
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Tired, bruised and happy. ;D
Quick post for numbers and pictures, I'll write more tomorrow.
Air, helium and what not.
First bullet 117g made 4215J on 2/3 helium air mix. Straight helium wont work on this valve, cycle time is way too fast. Needs more tuning in the valve for straight helium, but she will do more I'm sure.
Second bullet was 158g and cant remember what it made but 231m/s
The group is about 3" at 100 meters.
(http://i8.aijaa.com/m/00953/14424610.jpg) (http://aijaa.com/syRZaY)
(http://i11.aijaa.com/m/00389/14424611.jpg) (http://aijaa.com/76zQIt)
(http://i3.aijaa.com/m/00272/14424612.jpg) (http://aijaa.com/CJrvaE)
(http://i10.aijaa.com/m/00111/14424613.jpg) (http://aijaa.com/4Df2V3)
Marko
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Congratulations Marko..............3000 fpe + is really stout with out powder, and you FIN'S were first to do it..........WELL DONE.... 8)
Carl
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Thanks Carl,
Really happy how this turned out. Someone will surpass it surely some day.
Maybe we will brake the 4k limit this season, if all goes well.
Marko
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I think we will. Plain helium was a surprise with that valve, it didn't give more power, just opposite, but cycle was very sharp. Then mix worked out. Cycle wit helium only was more like in PB's. There will be helium for testing as needed, I promise.
It was also notable that with pure helium saboted 450gr bullet gave 3500J of energy at trigger point which was somewhere out of muzzle. We had to use doppler triggering with sabots and it was very difficult overall. Still got some numbers. That too tells about very fast cycle with helium.
Half moon club member.
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Thanks Timo,
And more like a quarter crescent moon club if you ask me, not a bad looking cut on your forehead.
Just a little eye makeup tomorrow I think. 8)
Marko
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No, its not bad at all and not affecting on eye colour I think. I have a hard forehead. The scars are the embellishment of the warrior. ;D
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Numbers mixed now, first bullet made 3985J and second, 158g, with speed 231m/s made that 4215J, 3109fpe.
I think we all are tired.
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3100 fpe ! INCREDIBLE @@@ absolutely amazing , almost pushing double the power of last yrs most powerful airgun ( 1760 fpe As I recall in 12 gauge )
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WOW!.... It is interesting that the Helium affected the valve dwell, not something than can be calculated.... Congratulations on setting a new standard for high powered airguns to be judged by.... Sorry about the wound, but as you say, the mark of a warrior.... I'm sure you wear it with pride....
Bob
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Thanks Bob,
Well the valve cycles fast on air and due to the construction of the valve it cycles way faster on pure helium.
It flows inside the contra piston so fast that the valve dwell is cut short and no power is gained from the speedy gas.
Testing will continue when time permitting, I will be starting edjucating myself for a better suited career and mechanical engineer studies will start this fall.
There is still lot to do on the Fury in terms of finesse, port polishing and what not, so there will be more to be had for sure.
One 4200J shot https://youtu.be/wcG76omqWbM (https://youtu.be/wcG76omqWbM)
Marko
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Some more video,
Shooting steel plate at 100m with a 148 gram bullet, but unfortunately target cam has no mic. https://youtu.be/uHQysu7UEtc (https://youtu.be/uHQysu7UEtc)
Then shooting 450gr sabot round at 490m/s on helium.
https://youtu.be/86lKPZqxFDo (https://youtu.be/86lKPZqxFDo)
Marko
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Some more video,
Shooting steel plate at 100m with a 148 gram bullet, but unfortunately target cam has no mic. https://youtu.be/uHQysu7UEtc (https://youtu.be/uHQysu7UEtc)
Marko
Its like a huge spinner! Awesome!
-
was there a sonic crack in the last video?
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Now that I picked my jaw off the floor all I can say is WOW!!!
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Weight of that plate is about 9 pounds and it is @ 100 meters...
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WOOF
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was there a sonic crack in the last video?
It was epic, it was like long thunderclap ripping the air all the way to 100m labradar was following some shots up to 200m
(http://i1.aijaa.com/m/00663/14426574.jpg) (http://aijaa.com/jr11Uo)
(http://i5.aijaa.com/m/00470/14426575.jpg) (http://aijaa.com/N6mu46)
Marko
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Now that I picked my jaw off the floor all I can say is WOW!!!
I know how you feel, first shot with real pressure was like Wow!
I'm so sad we forgot to record when I shot the smaller plate, it was hanging from a piece of conveyor belt, the bolt and washers came trough the rubber and the plate flew like a wet rag. Found it 2m from the impact point. :o
Well need to do it again next time we are out on the range.
Marko
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https://youtu.be/86lKPZqxFDo (https://youtu.be/86lKPZqxFDo)
Marko
That is so BAD ASSED Marko...lovin it! 8)
Al
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Thanks Al,
Glad that you like it, its been quite a journey to get to this point. We have some new desings in mind and new ideas to try next but it's on a longer list of things to do. ::)
It took longer than I would have liked but I lost interest at one point because of the dumb dump valve not working the way I wanted.
But now the gun works the way I like and its repeatable, minor things to do and it has an appetite for o-rings if not tuned right for given gas and projectile.
Marko
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Some more video,
Shooting steel plate at 100m with a 148 gram bullet, but unfortunately target cam has no mic. https://youtu.be/uHQysu7UEtc (https://youtu.be/uHQysu7UEtc)
Marko
Its like a huge spinner! Awesome!
Thanks Chris,
The plate got some loving from those slugs, have not seen that happen before with an airgun, nor have I ever seen plate that big swung with an pb either.
(http://i5.aijaa.com/m/00338/14426608.jpg) (http://aijaa.com/Muq1Hz)
Marko
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You need to bring your own silhouettes if you want to shoot that one in competition ;D
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Why? Marko only needs one shot to the wood under silhuettes and everyhting goes down (or up). ;D
We actually saw that effect once when there was a can over wooden beam and shot was in the wood under the can. It took some 2m high jump up...
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Why? Marko only needs one shot to the wood under silhuettes and everyhting goes down (or up). ;D
We actually saw that effect once when there was a can over wooden beam and shot was in the wood under the can. It took some 2m high jump up...
That would count as shooting silhouttes in wrong order I believe ;) I wonder if the longest chicken flight record could be improved with this gun, 100M perhaps?
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Err.., no. It happened once when Teemu shot two with one bullet but they were next in order. It counted.
Well this is just joking of course, we are not supposed to shoot woods and that gun weights around 12 kgs and is very long. Besides the result could be that after shot there are no standing silhouettes nor the shooter. ;D
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I think that was sihouette competition on Pori like 4-5 years ago when I shoot Quackenbush .458 on that iron beam and those chickens jump few fall over....Thats was about all what I hit on that competition...That beam I mean ;D
Two silhouettes in one shot was somebody else and I think that was on Iittala last year... Bullet hit pig and then hit turkey at same shot IRC..
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Oh yeah that was Arto I think.
Marko
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WOW !!! Make all the other big bores look like BB guns !!! Outstanding !!
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Thanks Ray,
Yeah it really does. ::)
Marko
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By the way a bag of bird shot on your shoulder will cushion and lessen the felt recoil.. Worked great on sighting in a 12 gauge magnum slug gun..
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I used large folded towel, worked good also. Was pretty exhausting after 40-50 shots when testing.
Marko
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Marko , what about a small gas ram or spring in the stock tube connecting to the gun , recoil absorption
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The bird shot gives way when you shoot.. Keeps your eyes from rolling around in your head !!
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Good idea Rob, but too much trouble to make. Besides a gun like this should bruise you up a little. ;)
Marko
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Good idea Rob, but too much trouble to make. Besides a gun like this should bruise you up a little. ;)
Marko
LMBO!
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Shooter needs some Sisu for sure.
You should make some armor piercing tungsten sabots and test what is the thickest steel plate you can punch thru. Soon you will have your own hydraulic press channel, or pneumatic drill channel could be better.
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Shooter needs some Sisu for sure.
You should make some armor piercing tungsten sabots and test what is the thickest steel plate you can punch thru. Soon you will have your own hydraulic press channel, or pneumatic drill channel could be better.
Love me a man with beaucoup Sisu. Yes, indeed-y...
I'm half Swedish, half German, so I gotta have a fella with guts of steel, for sure!! ;)
Y'all are doing some awesome stuff waaaay up north there, good for you!!! 8)
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Hmm that makes me think, I do have some broken tungsten milling cutters that would make a nice penetrator for some rounds, need to look what sizes do I have.
Oh, a Swedish German girl, with that mix I bet you are cute. ;)
And a handful of temper I recon. ;D
Marko
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Hmm that makes me think, I do have some broken tungsten milling cutters that would make a nice penetrator for some rounds, need to look what sizes do I have.
Oh, a Swedish German girl, with that mix I bet you are cute. ;)
And a handful of temper I recon. ;D
Marko
Cute? ::)
I'll never tell, lol, but I can say I am tall, blonde, blue-eyed and slender... :-X
I don't really have much of temper, but I do have a ton of resolve...
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Temper or resolve, I got both the temper and resolve from our German part of the bloodline, and being Finnish, stubborn as a mule. ;D
Marko
Edit, yeah must be cute, best looking girls I have seen are Swedish or Norwegian.
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Back on topic, and less harassing Chikie. ::)
To color or not to color, is the big question. Black is always in fashion, but so many guns are black or blued.
Paint in the other hand is well paint, and while nothing wrong with paint it is more of a camouflage and that gets me thinking, shoud I just camo it up or blue the barrel, anodize, and what not the parts?
Marko
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I think dark green anodizing would fit well and you could spray it with black sanodye after dipping in green, it worked reasonably well when I tested it, creates a long lasting camo. Nothing wrong with bluing the steel parts either.
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blue and chrome , totally field target look ! :D
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Aren't anti-tank weapons usually olive drab or battleship gray? ;)
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Like this one which invented Aimo Lahti ;D Nice colors..
https://www.youtube.com/watch?v=Y9qHv_XEAZg (https://www.youtube.com/watch?v=Y9qHv_XEAZg)
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Like this one which invented Aimo Lahti ;D Nice colors..
https://www.youtube.com/watch?v=Y9qHv_XEAZg (https://www.youtube.com/watch?v=Y9qHv_XEAZg)
I fired A Lahti at a 50 BMG competition sight in day............At a barrel at 1 mile..........Guy owned one and let others try it out a few rounds. This about 1992.......... You could buy one then for $2,500 with a BATF $200 tax stamp. The SOLOTHURN 20mm at that time cost $7,500 and were more scarce.
Carl
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The Lahti gun colors would be nice but the airtube is stainless and that needs to be painted.
olive drab or tan or something, need to think about it.
Blue and crome? You serious Rob?
Anyone good with photoshop cos I'm not?
Marko
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no , I'm not serious .. I like the other guys ideas ( anti tank camo )
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Oh, you got me worried there for a second ;D
Gamo is interesting choice for sure.
Marko
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Do the brightest flouresent colors you can.. If your going to make a scene be seen !!!!!
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Marko , all kidding aside, you should call Guiness book of world records, I don't think any other RIFLED airgun in the world is pushing 3100 fpe
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Well I don't know if I want that kind of publicity, need to think about it.
Marko
-
Well I don't know if I want that kind of publicity, need to think about it.
Marko
good point , they will throw you on a database and/or watchlist, probably waterboard you for a few days .. scratch the idea.
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It was my intention to shoot todays 200m (~220yds) benchrest with the Fury just for the fun of it
Well the hard cast bullets didn't work as I planned to roughly sight in on them and start my 2x10 round shoot.
Was really having difficulty to get on paper, and when I ran out of sighter bullets a quit and desided to get on paper no matter what.
Well 2% mix worked but it settled so slowly that I got only 3 on paper I was shooting high on them. And then the gun ate an O ring again. Called it quits and will visit this some other time again.
Was a bit frustrating day.
(http://i1.aijaa.com/m/00089/14440949.jpg) (http://aijaa.com/6WmiOS)
Marko
-
Them's BIG holes in that paper, Marko !!!
Bob
-
Yep they sure are big.
Was shooting low some bullets and one of my targets got covered with wet dirt, it sure kicks alot of earth up in to the air when hitting ground. ;D
Everything is on hold due to the engineering school. My algebra is really rusted. :o
Marko
-
Maybe some of your school projects will be airgun related!
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Maybe, thats a big maybe. I dont know how the teachers react to that.
But definitely I'm going to try. ;D
Marko
-
We have been joking Marko could be the first airgun engineer in Finland if not in whole wolrld. 8)
But then, why not? It is very technical and scientific.
-
That would be something, but that depends on lot of things.
It's pretty amazing thaf I actually got in to the University in the first place. There were like thousands of applicants and only 80-90 got in mechanical engineering. :D
I was told that its the best University of applied sciences in Finland. But I don't honestly know.
Marko
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Best or worst Marco, I'm sure you'll make the best of it!
pv
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We have been joking Marko could be the first airgun engineer in Finland if not in whole wolrld. 8)
That would be awesome!
-
That would be something, but that depends on lot of things.
It's pretty amazing thaf I actually got in to the University in the first place. There were like thousands of applicants and only 80-90 got in mechanical engineering. :D
I was told that its the best University of applied sciences in Finland. But I don't honestly know.
Marko
Congratulations Marko, that is already an accomplishment!
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Thanks,
This just means that there is less time for hobbies but more money. And that helps normal life some.
Insurance company pays my education and that is a good thing, I have "job" now for next four years.
My math is really rusted after some twenty years of working and not using equations that I learned in school. Now I need that long ago formated part of my memory. :o
Marko
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My math is really rusted after some twenty years of working and not using equations that I learned in school. Now I need that long ago formated part of my memory. :o
Marko
Reformatting would be less work and render better results, hun..
Start with a clean mental slate, add fresh input, compute! ;-)
:-) chickie
-
Recourse to computing is like navigating by GPS only on a dark sea. When you have a power outage, what you do? You get lost.
-
Reformatting would be less work and render better results, hun..
Start with a clean mental slate, add fresh input, compute! ;-)
:-) chickie
Well Chickie darling my mental slate is pretty clean already. I'm trying to keep up with the youngsters fresh out of high school. They still remember everything, but they have no experience on anything beyond school.
Its hard work to study but I've been in worst situations in my life.
Marko
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Reformatting would be less work and render better results, hun..
Start with a clean mental slate, add fresh input, compute! ;-)
:-) chickie
Well Chickie darling my mental slate is pretty clean already. I'm trying to keep up with the youngsters fresh out of high school. They still remember everything, but they have no experience on anything beyond school.
Its hard work to study but I've been in worst situations in my life.
Marko
I am sure you will catch right on and outpace them all in no time, Marko, but it surely must be an adjustment for you. The human mind is very plastic, and will bend to your will given enough, well, will, lol..
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Well my mind hurts from all the thinking. ;D
Found a nice picture, bullet in flight just before vapor cloud expands to hide it.
(http://i6.aijaa.com/m/00710/14468085.jpg) (http://aijaa.com/sOCBn4)
Marko
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When your barrel is bigger than your air tube you know you have a BIG bore!!! That thing is crazy!!! In a good way
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When your barrel is bigger than your air tube you know you have a BIG bore!!! That thing is crazy!!! In a good way
Yeah I know, and it would be nice to see what a bigger airtube would do to the power, more than give slightly better look to the gun.
Marko
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Yeah with the pressure dropping from 265 bar to 200 during the shot (on the one I found, others may vary).... that is nearly a 1000 psi drop due to reservoir size.... If you doubled the reservoir, you would cut that in half, increasing the average pressure during the shot significantly.... which should increase the FPE even further.... I would estimate about 7%, or about 200 FPE....
Bob
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Oh well, so not worth the trouble of making a new cylinder. Some other modifications will be tested next spring. I'm all in all very satisfied how the valve turned out, it's pretty flexible on how it can be used and tuned.
Marko
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Made an interesting discovery when inputting bullet data and velocity in a ballistic calculator. Data is from labradar, and calculated g1 bc is 0.701
Bullet drop is about 10mil / 100m from scope zero. Energy retention is very good.
(http://i3.aijaa.com/m/00048/14488134.jpg) (http://aijaa.com/BaBj20)
Marko
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And some fun, Fury vs laptop https://youtu.be/I_Fjch-dFZw (https://youtu.be/I_Fjch-dFZw)
Then a muzzle vapor cloud. https://youtu.be/zUHpgURPhII (https://youtu.be/zUHpgURPhII)
Marko
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That is just awesome! Energy and ballistics are just something I never thought I would see from an airgun, especially on air. If you ever bring these to production, the questions will arise, "can I put an LDC on this to make it back yard friendly?" ;D Nice work!
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That is just awesome! Energy and ballistics are just something I never thought I would see from an airgun, especially on air. If you ever bring these to production, the questions will arise, "can I put an LDC on this to make it back yard friendly?" ;D Nice work!
That's what oil drums are for ;) It is actually a bit loud, I was doing bullet testing on the next bench when Marko shot that laptop and I must say I pulled a shot or two.
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That is just awesome! Energy and ballistics are just something I never thought I would see from an airgun, especially on air. If you ever bring these to production, the questions will arise, "can I put an LDC on this to make it back yard friendly?" ;D Nice work!
That's what oil drums are for ;) It is actually a bit loud, I was doing bullet testing on the next bench when Marko shot that laptop and I must say I pulled a shot or two.
Lol!!
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That vapour cloud video is proof positive that the air in a PCP cools during the shot.... I wonder if that is water vapour or ice crystals?....
Bob
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Bob, it is proof of pressure change. Shock wave causes pretty high local pressure differences and steam comes visible under dew point which depends on temperature and pressure. In this phenomen pressure is the most remarlable thing although there is also small temperature change. But also sharp bullet track is visible in another views and if bullet friction in air changes temperature, it should rise.
I don't know if Marko would like to show that by picture or not.
Condition at the time of shooting was quite cold and very moist, not far from 100% RH.
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Timo if you have the pictures on you computer can you post them?
Marko
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Sure. I don't know if this gif is good here but here it goes:
(http://oi63.tinypic.com/15aud4.jpg)
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So, the bullet is long gone and major cloud comes after. But bullet draws a trace after it.
This animation is composed of still views from 120 fps video.
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Thanks, it looks amazing. And that high speed was worth the bruising. ;D
Marko
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The bullet is moving MUCH faster than the air, you can tell by how far they move in each frame.... I don't see any "shock front" disturbing the air near the muzzle, only a cloud of air being released.... Adiabatic cooling as the air expands does occur in any PCP, that is why barrels get colder with each shot, not hotter.... It would just be interesting to know how cold the air gets.... I still think the cold air from the muzzle blast is lowering the dew point of the surrounding air as they mix together, and causing the condensation.... The vapour trail behind the bullet is a different mechanism....
Bob
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Of course the air temperature goes down, air is expanding and we are extracting energy from it. The aluminum muzzle brake is frosted every shot, the temperature difference is around 10-15 deg C.
There is a compression front just in front of the muzzle that is visible for fraction of a second before the cloud expands. The highspeed footage is to pixelated to show it.
But its just at the moment the bullet exits the muzzle.
Either way, it looks cool as the cloud condenses. But there is no ice crystals forming, not enough temperature difference.
Marko
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It is true air cools down and sometimes we've had even layer of ice on barrels. But helium does not cool down because it's Joule-Thomson coefficient is negative. It does not even condense water from air humidity on barrel. Still we can see similar steam cloud from the muzzle.
Helium warming when pressure drops is clearly noticable when I fill up my smaller tanks from big bottle of helium. I have pressure regulator on big bottle and I adjust flow for compressor. When there is full pressure in big bottle and I start filling I can clearly feel regulator warming by hand. It doesn't come hot but warming is real.
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The aluminum muzzle brake is frosted every shot
we've had even layer of ice on barrels
Those two observations are great evidence that the cooling is significant, especially when you consider the mass of the muzzle brake or barrel that has to be cooled by the mass of the expanding and cooling gas....
The Joule-Thompson coefficient is a different thing than Adiabatic cooling on expansion.... The J-T effect occurs during reversible expansion, not the free expansion that occurs on firing.... The specific heat of Helium is different than air, however, so it may not cool to the same degree as air during a shot.... In any case, interesting observations, we can learn from them....
Bob
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I want to know how overkill one can go with valve and porting, so this should be interesting.
Savage .457 barrel fitted to the Fury frame.
(https://img.aijaa.com/m/00483/14596021.jpg) (https://aijaa.com/e0qN0V)
Marko
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lol, the 457 barrel looks like a pea shooter on there ;D this will be supersonic
-
And that is 815mm long barrel. Still it looks small. ;D
-
;D Unreal... It sending projectile so freaking fast if everything works like should.. Hope you get Labradar information
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Oh well, range day was not a complete success. Did manage to get some numbers with labradar, but in the hastened packing episode before leaving home to the range and I picked the wrong ammo box from the table.
So had only 292gr bullets to shoot, when I was planning to go from 290 to 620gr
Well the valve worked ok with the slugs we got, got 346 m/s (1135fps)with the 292gr bullets on 300bar. So some 835fpe I think.
Timo had some bullets that were slightly heavier but I dont remember the speed or weight.
Timo can comment on those.
There should be more there I'm sure.
Did shoot couple of groups on max pressure but nothing too special, maybe within 2" or something.
This was a quick test just to see how the valve reacts. And I will visit this thing again with more heavier bullets.
Marko
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Nice first outing.... I will be particularly interested what velocity you get using bullets in the 450-500 gr. range at 300 bar....
Bob
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Thanks Bob,
You and me both, had a box of sorted bullets from 292, 340, 360, 385, 450, 500, and 620gr if I remember all the weights correct. But just had to pick the wrong one. Already had 290gr box in the bag and took one with weight sorted 292.1-292.3gr box. Had the box lids mixed up, and didn't look inside. ::)
Marko
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Something like 390 gr were the heavier ones I had but they were sized down to .452 as you've should of have .457. I don't remember exact speed but do remember max. KE we calculated. It was 1240 J (914 fpe). So the speed must of been something like 313 m/s (1027 fps) by calculation.
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Something like 390 gr were the heavier ones I had but they were sized down to .452 as you've should of have .457. I don't remember exact speed but do remember max. KE we calculated. It was 1240 J (914 fpe). So the speed must of been something like 313 m/s (1027 fps) by calculation.
A friend showed me his method with his .45-70 Sharps years ago...
https://www.youtube.com/watch?v=-McT8ZI2tV8&index=5&list=PLOPetCyMvzsTnxVXowilA1zFcmX_Hfp_0 (https://www.youtube.com/watch?v=-McT8ZI2tV8&index=5&list=PLOPetCyMvzsTnxVXowilA1zFcmX_Hfp_0)
https://www.youtube.com/watch?v=bM23a_tbE-M&list=PLOPetCyMvzsTnxVXowilA1zFcmX_Hfp_0 (https://www.youtube.com/watch?v=bM23a_tbE-M&list=PLOPetCyMvzsTnxVXowilA1zFcmX_Hfp_0)
https://www.google.com/search?rlz=1C1GNAM_enUS688US688&ei=chNcW8f9I4fLjwSSkJ6oBg&q=paper+patching+.45-70&oq=paper+patching+.45-70&gs_l=psy-ab.12..0i22i30k1l2.2716830.2740248.0.2749484.29.26.2.0.0.0.308.3710.0j21j2j1.24.0....0...1.1.64.psy-ab..3.26.3711...0j0i67k1j0i131k1.0.CcSZKGZ3bUQ (https://www.google.com/search?rlz=1C1GNAM_enUS688US688&ei=chNcW8f9I4fLjwSSkJ6oBg&q=paper+patching+.45-70&oq=paper+patching+.45-70&gs_l=psy-ab.12..0i22i30k1l2.2716830.2740248.0.2749484.29.26.2.0.0.0.308.3710.0j21j2j1.24.0....0...1.1.64.psy-ab..3.26.3711...0j0i67k1j0i131k1.0.CcSZKGZ3bUQ)
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In this case paper patching was out of the question because it still is 20 mm upper equipped with .457 barrel just to see what happens. When Marko forgot his "loading aid" home, it looked difficult to load. ;D
Anyway, here is a video of the fight results against some tins of smashed tomato something and one fruit coctail with light weight HP. I bet it was supersonic, but did we even measure? ::)
youtu.be/_X27M0ailUo (http://youtu.be/_X27M0ailUo)
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Well it was like 30deg C in the shade and everyone was more than exhausted from the heat.
Very unusual to have so hot wether for so long period here.
I dont have so good tolerance for heat anyway so I'll blame it on that.
Still interesting results on the first tests.
Marko
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Maybe a tad too much power....if you go hunting with that thing there won't be anything left for dinner!
Verrrry Cool!
pv
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Errr.. we actually can't hunt anything here with airguns so there will be no wasted meat.
-
Exept those tincans full of fruitcoctail or tomato ;D
-
I can say that must have been a literal BLAST to have fun with. ;) 8)
-
Yeap, it was fun!
Loadin it was a pain without the sleeve I made for smaller projectiles, it was real easy to get the bullet in the transferport. ::)
Marko
-
This thing is insane. You should probably begin production and sales.
-
Thanks Matt,
Unfortunately I can't do that, need to be certified gunsmith here in Finland to make bigbores for sale.
And that would require four years of education.
So this will be one of its kind.
Marko
-
Season ends here in Finland, land of the crazy and thousand lakes.
I don't know if it's just me but the further from "sane" we get the more interesting it gets.
More materials to be ordered and parts to be made, there is more power to be found.
The way I see it, if it can be broken with one caliber it can be done with others also.
;)
Stay tuned
Marko
-
Season ends here in Finland, land of the crazy and thousand lakes.
I don't know if it's just me but the further from "sane" we get the more interesting it gets.
More materials to be ordered and parts to be made, there is more power to be found.
The way I see it, if it can be broken with one caliber it can be done with others also.
;)
Stay tuned
Marko
LOL! Looking forward to it! ;D
-
;D Well need to pack pair of clean underwears when shoot that "thing" next time :P
-
Did fix one warranty cell phone case back at the season ending.
Forgot to post it here.
There is four shots in the middle hole, I first aimed at the same spot and thought the dispersion would do the rest, then I had to start aiming on different parts to get more holes.
Cant remember distance if it was 25m or 50m but it doesn't really matter here, it's just for fun anyway.
(https://img.aijaa.com/m/00189/14629312.jpg) (https://aijaa.com/3yFvrR)
Marko
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Lets dig this one up from the past, have been making drawings and calculations.
I will be making a new bigger valve and double the volume of the air tube.
Should get me closer to the next thousand fpe mark.
Some of you might call it for bragging rights, or show off. But my intention is just to see how much there is to be had.
And having one of the most powerful airguns, one can be bragging a little?
Nothing mysterious in it, just a big valve and a long barrel. You just need to make sure every part of the gun is more than rigid enough.
Marko
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At what point do these become "Air Cannons"? LOL!
pv
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Get busy making parts Marko. I need some inspiration to get a couple of my projects past the idea stage .
-
Guau...
An air rifle to hunt dragons.
-
Long time on this one but I made a small features video on the gun if anybody is interested.https://youtu.be/9e5w4lqw1c0 (https://youtu.be/9e5w4lqw1c0)
New parts are delayed for the obvious reasons we all know. But I have access to a bigger lathe again from next week so maybe we'll see some new stuff before the fall.
Marko
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That is absolutely gorgeous!!! Really, amazing work!
Whew!! I thought MY builds were too long! ;D
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Thanks Tom!
Nah, I dont think your builds are too long! Even mine fits in side the AiM 60 size dragbag. If I remove the buttstock but still. ;D
Marko
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Thanks for the video!
Real nice to see some close ups and you work is as always real pieces of art! ;)
-
It's funny- re-watching your vid a few times, you've made what I've had in my head for a long time!! It's nice to see the concept actually works! I had/have no way to make what you have- but still... VERY nice!
-
WOW! Whats to say but Amazing work.....Nothing like it.
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Thanks guys,
I'm really tempted to build a second one but with lighter barrel and bullpup design. I still have one more madsen barrel in stock. 8)
1000cc carbon tank and make it so that it could be shot without a rest. Maybe a next winter project if I don't have too much other stuff to take my time.
Marko
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And here we go again, some update parts for this.
First cut with carpenter tools
(https://i.ibb.co/0YkcDfx/E6516-A78-86-BB-4-AD9-AD2-C-9-E58-ADB09-C44.jpg) (https://ibb.co/vLbHwJS)
Next with drill and boring bar. Not fun to cut 145mm with short bar, only 30mm in the holder.
(https://i.ibb.co/k9sdqyQ/0076-AA4-D-9-EF0-4-C1-D-BF77-01012-B7-F77-E1.jpg) (https://ibb.co/3M9JSsB)
Next thing is some more turning and then in to the milling center. ;)
Marko
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This is my first time seeing this build…..excellent work my friend, just excellent.
Dave
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Thanks Dave,
It has been in the background with so many other projects. But now I have some time to make a new valve frame before the winter is here and season ends.
This time just might actually have time to finish the frame and not leave it so rough.
Marko
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nice, cant wait to see 4000 FPE
-
Thanks Rob,
You and me both!
Just not sure if the air tube is big enough, It should be close to enough and the bigger valve will help.
Marko
-
Turning work done, next step will be in the machining center.
(https://i.ibb.co/2jMv2Ts/5-B6-FC8-BE-3-AD3-4-FC7-BF34-687-E5-B4983-C2.jpg) (https://ibb.co/FBY5vF0)
That will probably be next weeks stuff, need to help bro this weekend.
Marko
-
Got to finish the cad model exterior the way that is visually pleasing to me.
Now just need to make the tool paths with cam.
(https://i.ibb.co/frZg8h1/C0677-AF2-E8-C0-483-A-8-C1-B-F389-BE97-A7-ED.jpg) (https://ibb.co/0Y17BgD)
Should be now more refined looking build than before.
Marko
-
nice is that the valve block?
-
Yes,
New valve block with completely redesigned valve. Dwell can be adjusted with a screw.
Marko
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Ok, you know you got my attention on the valve.
Dave
-
Making some shavings finally.
First setup is something like 12000 lines of g code.
Next after that is 40000 lines.
(https://i.ibb.co/4SGH5tg/0-BF253-B5-D2-E3-42-E0-8-E7-C-FFC5-D4-C4-C0-C2.jpg) (https://ibb.co/hdjSt91)
5mm of excess removed and hole started, next is 3D contour in to the hole bottom to create a radius.
Marko
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I can come and measure the transfer port if you need help.
(https://live.staticflickr.com/65535/50426336917_5965f267d9_c.jpg)
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I thinks your thumb will fit better now. ;D
Marko
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Thanks guys,
I'm really tempted to build a second one but with lighter barrel and bullpup design. I still have one more madsen barrel in stock. 8)
1000cc carbon tank and make it so that it could be shot without a rest. Maybe a next winter project if I don't have too much other stuff to take my time.
Marko
I could see this being a viable rifle for hunting moose or grizzly bear in a bullpup design with an attached or portable bipod. A bit heavy, but useable in a stand I imagine. This rifle may even make the hunt more challenging! I'm surprised to learn, from this thread no less, than Finland has no legal air rifle hunting. Can people hunt their own land with air rifles?
-
No hunting with any air guns no matter what caliber or power. Own land or not. Laws take forever to change, and law makers are really clueless on what can be had today.
Marko
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Watching, cannot wait to see what you can achieve... 8)
Jesse
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I can come and measure the transfer port if you need help.
(https://live.staticflickr.com/65535/50426336917_5965f267d9_c.jpg)
Is that a Metric or Imperial thumb? I usually have one or two imperial handy in my pocket but I'd never keep a Metric one in there. Creepy which ever way you take it.
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I can come and measure the transfer port if you need help.
(https://live.staticflickr.com/65535/50426336917_5965f267d9_c.jpg)
Is that a Metric or Imperial thumb? I usually have one or two imperial handy in my pocket but I'd never keep a Metric one in there. Creepy which ever way you take it.
Why imperial of course. As you can see the nail goes in by 13/16th of the length, not entirely as it would go in a metric rule of thumb.
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In case you don't know how big this gun is.... check out the photo in Reply #232 on page 12.... :o
Bob
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In case you don't know how big this gun is.... check out the photo in Reply #232 on page 12.... :o
Bob
It just looks big as I'm so small ;)
Well seriously, it's a huge gun and heavy, but it was never intended for hunting or something like that. Just purely built for fun and the weight helps to absorb some of the recoil.
Marko
-
Minor setback on machining. This was supposed to be ready this weekend but then this happened. Taking apart the spindle from the Z carriage.
(https://i.ibb.co/rQYfrxR/27-D2-F220-70-C0-4-FB7-B8-D7-DBCC31-A89424.jpg) (https://ibb.co/Gdy3SW4)
Apparently oil nozzle was clogged and one of the ways got oil starved. That and some old chips gotten in the ways from damaged wiper.
Two and half long days to fix the problem.
Way is stoned and it ok, the counterpart is lapped and usable.
So things happen with old machines, be sure to check the oilers now and then.
Marko
-
Glad it wasn’t worse. Sounds like you got it sorted.
:-\
Dave
-
Yeah, I'm glad too. Could have been the complete rail that got ruined but fortunately it was just some metal deposits on it.
Back in action again.
(https://i.ibb.co/D7jP36j/1-DBBA093-6-F58-4-E1-C-9139-42-D604-BC856-E.jpg) (https://ibb.co/JzSWXbS)
Marko
-
Good deal!
Dave
-
And about 100k lines of g-code later we have something that looks like the 3D model.
(https://i.ibb.co/grtxkPP/69-FBC12-D-AFE8-4024-89-BD-ED37-EDF76-A1-E.jpg) (https://ibb.co/yNgrHYY)
Just need to make the trigger group attatchment points.
Marko
-
WOW, just WOW!!!!.... :o 8)
Bob
-
Yep! That is amazing.
Nice work my friend.
Dave
-
looking awesome !
-
That's very nice looking. What are you going to do with the "weaker power" one?
-
Thanks guys,
Well Dan I dont honestly know yet, maybe make a slightly shorter tube for it and slap a .457 upper on it. Should be plenty valve and ports for .457
I do how ever have one 15.4mm smooth bore that is 1.5meters long...
Need to think about it, could make a nice frame for a pup. ;)
Marko
-
Thanks guys,
Well Dan I dont honestly know yet, maybe make a slightly shorter tube for it and slap a .457 upper on it. Should be plenty valve and ports for .457
I do how ever have one 15.4mm smooth bore that is 1.5meters long...
Need to think about it, could make a nice frame for a pup. ;)
Marko
Air shotgun?
-
Thanks guys,
Well Dan I dont honestly know yet, maybe make a slightly shorter tube for it and slap a .457 upper on it. Should be plenty valve and ports for .457
I do how ever have one 15.4mm smooth bore that is 1.5meters long...
Need to think about it, could make a nice frame for a pup. ;)
Marko
Air shotgun?
Yeah. A 12 GA would be about right.
-
15 mm is 20 gauge.
-
Lookin' good-WOOF but is that thing huge!!! 8)
Jesse
-
Air shotgun?
More like discarding sabots and finned dart projectile.
Marko
-
Air shotgun?
More like discarding sabots and finned dart projectile.
Marko
That is very interesting. 3D printed sabot body? What weight projectile do you have in mind? Sounds like a weapon from the Quake or Unreal series
-
Air shotgun?
More like discarding sabots and finned dart projectile.
Marko
Now that is one I'd like to see!!
Jesse
-
Air shotgun?
More like discarding sabots and finned dart projectile.
Marko
That is very interesting. 3D printed sabot body? What weight projectile do you have in mind? Sounds like a weapon from the Quake or Unreal series
Something around 300-500gr maybe. We have been using 3D printed sabots for some years with very good accuracy.
Marko
-
Saw your shooting video today on youtube, how is your shoulder? looks similar to my friends .50 bmg single shot.
-
Shoulder is fine, it was not all out for power. Still kicks but its manageable.
Had fun making the vid, shame that I was aiming too low on the flour pack, would have been better blow of flour.
Marko
-
I can come and measure the transfer port if you need help.
(https://live.staticflickr.com/65535/50426336917_5965f267d9_c.jpg)
Look how similar our blocks are! Even the mounting holes LOl. Got a big bore in the works also but very different valving system than yours I'm certain.
-
And about 100k lines of g-code later we have something that looks like the 3D model.
(https://i.ibb.co/grtxkPP/69-FBC12-D-AFE8-4024-89-BD-ED37-EDF76-A1-E.jpg) (https://ibb.co/yNgrHYY)
Just need to make the trigger group attatchment points.
Marko
Dude your skills are crazy good!!! Need a fulltime job in the USA?
-
Thanks,
But no thanks on the job, have been following the news there lately... oh my.
Land of hope and glory is slowly going downhill.
Marko
-
Thanks,
But no thanks on the job, have been following the news there lately... oh my.
Land of hope and glory is slowly going downhill.
Marko
I don’t know about slowly it’s more like a free fall. It will work it’s way back around.
-
Thanks,
But no thanks on the job, have been following the news there lately... oh my.
Land of hope and glory is slowly going downhill.
Marko
You almost quoted the "Writing on the Wall" by Iron Maiden there... ;)
Jesse
-
Oh yeah forgot to post it here, the video. That was mentioned earlier.
Only 280bar used on the shots so at only around 3100J power.
https://youtu.be/0NhwqddnzIE (https://youtu.be/0NhwqddnzIE)
Marko
-
More like discarding sabots and finned dart projectile.
Marko
You will need asymmetric section or angled fins on a dart type projectile to induce some spin, otherwise it will not be accurate. You will also need to design the correct amount of stability and spin to avoid resonance problems. Even defence manufacturers get it wrong sometimes.
Sabot design can be challenging as well.
-
So back at it again.
820cc of liquid in a pipe.
(https://i.ibb.co/HHgjY9t/E56-DC0-E7-0402-4-BDE-A45-D-D5778-B7972-FA.jpg) (https://ibb.co/XCJqpG7)
Ready to hydro test the new tube and block.
Marko
-
Hydro testing went smoothly,
OD change at 500bar 0.06mm and length 1mm
0 bar and back to where we started so no permanent deformation.
Setup
(https://i.ibb.co/Fz5xgnp/AB34-A442-3320-4-BF3-B0-B9-CB91107-E3-F06.jpg) (https://ibb.co/jDy6gHt)
Shield, machine 10mm polycarbonate glass, helmet and face shield.
(https://i.ibb.co/QQ6ZDmt/D8-D7-FC9-F-8-D29-4536-8660-ED4-D4217-D23-F.jpg) (https://ibb.co/4tjc1N3)
50Mpa / 500 bar in the cylinder
(https://i.ibb.co/Gx6Cf97/502-F7-B7-E-1114-4684-A87-E-8-E812257-CE35.jpg) (https://ibb.co/SsjVDcN)
No drama and I call it safe to use on 300bar fill.
Next test will be Alsafe carbon bottle. I don't trust to preasure it before hydro.
Marko
-
thats quite the airtube Marko , awesome
-
8)
Nice update!
Dave
-
WOOF! 8)
Watching!
Jesse
-
Thanks guys.
Some small parts to make and I can test the bigger valve and how it performs.
Going from 18mm to 22mm and over 50% more air capacity. More flow and no restrictions from the valve to the tube.
Going after the next thousand fpe mark.
Marko
-
That's .78402 caliber, right?
-
Please delete
-
That's .78402 caliber, right?
.807
-
If the human mind can imagine it, given time and resources---
-
Small update,
Valve retention block done
(https://i.ibb.co/Pt6mctT/53-B1-B682-A006-4-E9-D-897-E-6-E390-D9-EC8-ED.jpg) (https://ibb.co/rvw7xvb)
And adapter for Tikka swivel stock
(https://i.ibb.co/mtgHWCk/BDC6-ECCD-8-C15-46-E5-B02-B-9-A59-E8-B9-B3-A1.jpg) (https://ibb.co/S0GKCXb)
Now I can use off the self butt stock borrowed from Tac frame.
More to come, just one more week and should be ready to test.
Marko
-
And the shoe fits!
Side folding stock on loan from a friend. Before I can make aluminum version of my own. But no time now for that.
(https://i.ibb.co/99yrhyB/39-B0-D92-C-8-B8-D-4133-99-AB-362-F621-A6236.jpg) (https://ibb.co/pv4LQ4N)
And folded view.
(https://i.ibb.co/vxpZkn1/BAA9-EB2-E-A240-4-C06-9055-8-BAC5-D2-E9-E56.jpg) (https://ibb.co/27xgd4q)
Will be easier to transport the rifle without disassembly.
Marko
-
Say hello to my little friend ;D
(https://i.ibb.co/KGb3b8z/38-F2399-C-0-E88-46-A0-A8-B9-1-CDE7-D7-E6-B89.jpg) (https://ibb.co/JdmMmSF)
Marko
-
wow awesome.. it actually appears smaller than it used to be
-
Yep…awesome!
Dave
-
Thanks guys,
Well the bigger airtube makes it look shorter as it gives some heft to contrast the long barrel.
Its heavier slightly and it's going to be very interesting first shot with the completely redesigned valve.
No obstructions from the tube to the valve and its 4mm bigger than the previous one.
Marko
-
Just plain out and out awesome 8)
Jesse
-
That Tikka recoil pad should be better than your old setup. Good work!
-
In the words of my granddaughters... O. M. G. !!!!
-
Finally had time to engrave the name on the frame.
Turned out ok, should have made it more ragged looking, but its fine.
(https://i.ibb.co/T1LHy9w/DFC0-F95-C-DC2-C-48-C7-83-F1-FAB8-E056-EFD0.jpg) (https://ibb.co/YXZtgHN)
Tomorrow final assembly and hopefully it holds air.
Marko
-
Pre-NATO tank killer
-
Yep,
Need to upgrade it to be Nato compatible ;D
Marko
-
And when you forget the buckling factor...
if it was easy everyone would be making these.
(https://i.ibb.co/QJbRdfV/410-A4-ACD-58-E4-46-FC-8542-60098854-AF62.jpg) (https://ibb.co/mRDw8GK)
Valve connecting rod, calculated failure point 556kg compression, let go at 570kg about.
We sometimes forget something, and failure is a learning experience.
Marko
-
Excellent learning experience for all of us.... Thanks for posting that as a reminder.... 8)
Bob
-
Failure is a learning experience!
And I am constantly learning!
Dave
-
You all still talking about this Oerlikon.
-
Yes...
So I have come to the point in valve sizes and forces that plastic is no longer a viable option.
So we turn the next one from steel and titanium.
PEEK valve poppet pulled in half from the balancing force.
(https://i.ibb.co/n6hzMGp/0-B6-D8108-0938-4-B91-A190-25762800-FD33.jpg) (https://ibb.co/tQy8pGR)
Interestingly the cut follows the thread pitch line all the way to the outside.
Valve size is large.
Marko
-
Almost like the crest of the thread acted as a stress riser?
Dayum! :o
Jesse
-
First test and part failure. Doesn't matter we know it works.
200bar air and 3200J of energy. So there is more to be had.
Needs more spring and better material balancer cylinder cage.
Marko
-
3200 joules =2360fpe, not too shabby ;D
-
Its pretty good for 200bar and on the edge of valve lock.
150bar 2100J
180bar 3000J
200bar 3200
And after that no gains and the cage collapsed.
Failure was expected as I didn't have crmo big enough for the cage and made it out of mild steel.
Just so I can verify the new valve dimensions are good.
Failure mode is very predictable and nothing dramatic, gun bleeds out to empty after shot.
Now better cage out of crmo and more hammer spring.
Interesting times ahead.
Marko
-
New valve parts and a new day...
(https://i.ibb.co/TqrbMYL/69-CFFA69-2675-4054-939-C-685-B33-FE8721.jpg) (https://ibb.co/LhvJdY5)
upload pics (https://imgbb.com/)
Just some nice looking scenery.
Last time we had a part failure and I used the valve stem from that setup. Should have measured the part first.
Started where we left off last time.
Around 200bar, valve lock and new longer spring.
220bar 139g bullet 233m/s
240bar same bullet 236m/s so again closing valve lock and started leaking.
Took it apart and stem is bent. Back to the drawing board.
But we are getting to the last power mark with straight air and there is still some 60bar on tap.
Very happy on the performance of the new valve.
Marko
-
So 2852 FPE on air !!!!!!!!!!!!! insane ! nice work
-
Fantastic work, it's always great to see dedication to pushing the boundaries!
I also love the "anti-materiel rifle" look, it is somewhat reminiscent of the Steyr HS .50:
(https://i.imgur.com/cD9BWK9.png)
-
Thanks guys,
It's kind of my pet project, can't help it. Just like drag racing, trying to push the boundaries a little.
Need to enlarge the balancer slightly as the cocking force is too high for my liking.
Made and internal ssg as the recoil is starting to get out of hand when there is any hammer bounce on this power levels.
It's working really good, only one sharp report and recoil is snappy.
For now it's manageable but when upping the pressure to the 300bar then it's another story.
(https://i.ibb.co/1221LSX/C282818-D-A03-C-4-AE0-946-A-49-D7-D208603-A.jpg) (https://ibb.co/f00f2cN)
Hand getting slightly colored from the recoil.
Extrapolating the curve from previous shots we should see north of 5000J on 300bar with air alone.
If not I will be slightly disappointed.
Marko
-
New sturdier valve stem, 8mm gr5 titanium.
(https://i.ibb.co/Wg8NykD/0-A9373-BC-311-A-4-D1-B-B952-F8-A3-CF7-BB4-E4.jpg) (https://ibb.co/ChCp7bJ)
This will hold what ever I throw at it.
Marko
-
incredible !@
-
When your valve stem diameter is wider than most air rifle bores, you know it's serious business ;D
-
When your valve stem diameter is wider than most air rifle bores, you know it's serious business ;D
Now that you put it like that, I didn't think about it before.
It gives a certain perspective to the size.
Marko
-
Balancer cylinder modified, micro honed and hard anodized.
(https://i.ibb.co/1n0SR1c/69-DC2-A03-84-F3-4-A40-AA96-53-BEB3-ED25-CF.jpg) (https://ibb.co/yRN3gt2)
Hard anodizing is the same as normal, you just need to keep the solution cold, and use enough current.
On 7075 when the surface is getting darker gray you got a decent hard anodized surface.
Scribing tip just glides on the surface without leaving a mark.
Marko
-
Inconel for valve stem?
-
Gr5 titanium, need to keep the weight down. There is quite substantial inertia in the moving parts while the valve cycles.
Marko
-
Testing done, should be ecstatic but slight hint of disappointment.
Valve dwell is little too short for heavier slugs.
As the weight doesn't give much difference in power, only around 100 extra joules.
Heaviest bullet shot yesterday.
(https://i.ibb.co/G3g62DV/BA52-E666-BE48-46-D3-BD25-C45-B7-BAD6-AE4.jpg) (https://ibb.co/n8hGcyD)
And one of the velocity readings for that.
(https://i.ibb.co/Jcz3FdB/6-E0-E8899-7066-42-B0-B1-C4-D0945087-EC29.jpg) (https://ibb.co/XWzYk42)
4089J or 3016fpe on 300bar air alone.
Pretty happy that we are on the same power levels on air that we got on helium air mix with the last valve system.
Oh yeah for got to add, the light 95g bullet goes on average 284m/s
Good speed and ok energy retention, drops to 268m/s at 100m
Marko
-
congrats Marko.. over 3000 fpe is insane ! ;D
-
Seems sane to me :)
-
I wonder what accuracy is with that slug fired backwards.
Dave
-
Thanks guys,
Well accuracy is pretty good with any of the slugs I have for it, and it's pretty same if shooting them backwards.
If you manage to hold the beast without shifting throughout the shot it's going to hit where the crosshairs point.
Some lighter slugs
(https://i.ibb.co/KLQXrQK/8-A9-D1-BCD-D976-4-A8-C-8429-B72-B9-BFF71-F3.jpg) (https://ibb.co/z7Lr4L6)
New mold from old
(https://i.ibb.co/jMQ1CxZ/6-E85-A890-B3-C2-45-B4-8-F96-A63927238-D72.jpg) (https://ibb.co/yyZbzMB)
Marko
-
recoil is snappy.
Looks like a muzzle brake should help. One that looks like a field howitzer brake should do the job. Possibly a bit like this; or flat without the cones to make it even simpler to machine:
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=200294.0;attach=405191;image)
This one has features to enable 3D printing, that can be deleted for machining. You may want a threaded barrel stud version...
-
Dose your mold ever have issues moving or warping when it gets hot? That thin bit between the cavitys looks like they will flex when heating up to me.
-
Dose your mold ever have issues moving or warping when it gets hot? That thin bit between the cavitys looks like they will flex when heating up to me.
I was thinking the same, but looking at where the large cavity reaches the outer edge. That bit is even thinner.
-
recoil is snappy.
Looks like a muzzle brake should help. One that looks like a field howitzer brake should do the job. Possibly a bit like this; or flat without the cones to make it even simpler to machine:
I have a muzzle brake, flow optimized 3D printed from stainless steel.
Without the brake recoil was intolerable.
Marko
-
No issues with mold warping on any of my molds. Not the first ones to wonder that, and I'm kind of curious why is everyone thinking that?
Never have had any issues with molds, none. I don't generally treat the molds too gently but they just keep working.
And I'm not too concerned as I can make a new one just by putting a raw one in the lathe and pushing a button.
Marko
-
I have a muzzle brake, flow optimized 3D printed from stainless steel.
Without the brake recoil was intolerable.
Marko,
Do you have pictures of the brake. Please post them if they are handy.
-
No issues with mold warping on any of my molds. Not the first ones to wonder that, and I'm kind of curious why is everyone thinking that?
Never have had any issues with molds, none. I don't generally treat the molds too gently but they just keep working.
And I'm not too concerned as I can make a new one just by putting a raw one in the lathe and pushing a button.
Marko
I was curious because I accidentally warped a .22 cal NOE pellet mold using a rocket stove to melt my lead. Maybe less material is better?
-
I need to take a picture of the brake. I have deleted all the old ones.
I always preheat the molds before pouring lead in them and never had a problem.
Have seen warped molds at swap meet and even bought one as I can mill it and use it as a core.
Marko
-
Couple of pictures of the muzzle brake.
(https://i.ibb.co/yN4C2X2/87-C31-CBF-17-B6-4-BEB-8572-3-B26-D316-F1-E4.jpg) (https://ibb.co/qDJ86d6)
(https://i.ibb.co/6vzRGnT/25-EBF647-24-F8-4-D9-C-B8-DE-47-A2-EA61-DEE6.jpg) (https://ibb.co/WDZW7xM)
3D printed in stainless steel as it is impossible to mill that out of one piece.
Marko
-
Thanks Marko,
The brake is a thing of beauty. Looks like it directs the air backwards by a few degrees, for more recoil reduction than just rocket effect cancellation.
Do you have an equivalent recoil to compare it to? Something like a 1.25 ounce 12 gauge slug at 1600 FPS, shot from a 7 lb shotgun.
I presume you have to use good hearing protection to shoot this thing.
-
I'm curious as to the strength of 3D printed stainless steel?....
Bob
-
I'm curious as to the strength of 3D printed stainless steel?....
Bob
Material data sheet says ultimate tensile strength for H900 1180-1230MPa if I read it correctly.
Marko
-
Thanks Marko,
The brake is a thing of beauty. Looks like it directs the air backwards by a few degrees, for more recoil reduction than just rocket effect cancellation.
Do you have an equivalent recoil to compare it to? Something like a 1.25 ounce 12 gauge slug at 1600 FPS, shot from a 7 lb shotgun.
I presume you have to use good hearing protection to shoot this thing.
It's loud, recoil is different from powder burners it's longer. But intensity is worse than Barret 50cal
Marko
-
Marco what 3D printer was used to print the brake?
-
Markforge before they forbid to print any parts of guns.
Marko
-
those printers run about 1/2 a million dollars.
-
Impressive, that is more than double the tensile of most stainless steel (304 is only 515 mPA), and the same as heat treated 17-4PH H900 bar stock.... I had no idea that printed metal was the same strength as solid.... :o ???
Bob
-
Marko,
I hope this does not highjack your thread:
As commercial 3D printers don't allow orders for "gun parts", perhaps there is a way to make another version or copy of your muzzle brake. The images below are for a 20 mm diameter projectile, using a 2 mm radial clearance (arbitrary):
The brake is fabricated from individually machined baffles, that locate in grooves, and are welded to the top and bottom cover plates. I used 5 plug welds per baffle per side, but that could be increased.
The parts can also be brazed together. Then the plug weld holes would be left out. Either way, a mandrel would be used to keep the baffles coaxial while welding, or brazing. After rounding the OD as shown in the bottom images, the baffles could be line bored to final size, if the mandrel arrangement was not satisfactory.
The baffles start life on a lathe, machined front and rear. Then flats are milled, top and bottom. The cover plates are milled, with tapering holes for the plug welds to attach to the baffles.
The rear baffle has a split spigot to form a "collet" that is a snug fit on the front of the barrel. Rather than complicate the rear baffle part by machining in or welding on the clamping screw support structure, I just selected a stock industrial hose clamp to close the collet against the barrel. Four slots are arbitrary, chose for machining simplicity and adequate flexibility.
The shape of the baffle curvature is arbitrary, although I tried to model it on your brake by rough visual scaling. This curve could be simplified for manual lathe machining, if a CNC lathe is not available. A large form tool could be made and used, although that seems like not a friendly machining job. Using a rotary table on a mill may be easier, and enable ball nose cutters to approximate the desired baffle face curvature.
The last images show how the welded assembly could be rounded in a lathe to reduce unnecessary mass.
The attached ZIP file contains the the assembly with all part in STEP file format. Both as welded; and as the version after rounding in a lathe (nicer looking).
Anyway, I did this purely as food for thought, in case you wanted more brakes with your flow design, or different ones. And, as you stated, the design cannot be CNC machined in one piece. So, if you can't print them anymore; how can they be made? Like this.
I could adapt this design to bolt together, but would need to make the baffles thicker in places to accommodate the bolts.
-
Forgot to attache an image of the lathe turned precursor baffle shape; before the flats are milled. This precursor part could be milled using a rotary table, in place of a lathe:
-
That just shows how much the 3D printing changes the way manufacturing industry is evolving right now.
Shapes that are not possible or cost effective to make are a reality today.
Let's not go in to this subject more in this thread.
I have some small upgrades planned for chamber sealing, having some blow by from the bolt. Seems that the lip type seal needs a backing ring.
Marko
-
We pushed the boundaries of airguns in to the new level. Air helium mix, and there is a lot of recoil and I seriously mean alot!
5966J / 4400fpe on 310bar, very limit nearing the valve lock.
It's insane, and nothing holds together for too long. More info coming when we get all the pictures and videos sorted.
Bruised and happy ish, so close to 6kJ... one day.
Marko
-
Very impressive!
-
W O W !!!!
Bob
-
Just went back and looked up the numbers on the barrel.... If they haven't changed, the bore is 0.807" and the length is 43.3", for a bore volume of 22.14 CI.... At 310 bar (4500 psi) the maximum possible FPE (including all losses), if the pressure remained constant, and including the energy to accelerate the air/helium, would be 8300 FPE.... On air, my "lofty goal" would be half that (4150 FPE), and you are beating that with an air/helium mix.... Getting to 3016 FPE on 300 bar of air is nearly 38% of the maximum, which is a fabulous achievement with such a colossus, IMO.... Congratulations, Marko !!!!
My guess is that on pure Helium, you will pass that 6,000J goal quite easily.... 8)
Bob
-
Wow ,,,,,Legend status achieved....
-
Thanks guys,
It's been quite the journey, set out to make something different and not in my wildest dreams excepted t to achieve so much power from an airgun.
It's actually more accurate than I imagined but it takes way more to handle than I honestly am capable shot after shot.
It will rough you up pretty good every time pulling the trigger. 2-3 shots is somewhat manageable but after that it's starting to get painful and less accurate.
Will post video when a friend gets them edited and pictures in a day or so.
There is something different with 95 gram projectile going past supersonic, like thunder in the air as it rips the sound barrier.
Valve broke twice today, first time it stuck flat out open, I can assure it hurts. Very violent ordeal. Second time the balancer just started leaking and we got one shot on two 5L waterjugs to finish it off and end the day. Just leaking and no drama.
Marko
-
OUCH !!!!.... I know what a tank dump is like on a 200 FPE airgun, I can only imagine!!!!.... Regardless of how much energy ends up in the bullet, your shoulder is probably feeling the recoil from 7000-8000 FPE every time you squeeze the trigger.... Maybe more if the valve is open until after the bullet exits the muzzle (which is likely).... :o
Bob
-
Mercy! I have had a valve dump with a Texan before and it was quite alarming. I can’t imagine what that beast your working with would be like.
Excellent work!
Dave
-
4400 fpe , i dont think we will see that from crosman any time soon.. congrats Marko.
-
I had to look up a rifle cartridge power chart to really get a grasp on just what 4400+ FPE means; short of it being 209 times more than my pop-gun Diana 350 pushes in a shot...
HOLY TOLEDO!....
You're only in the same power category as the .338 Lapua Magnum.... :o :o :o :o :o :o
Congratulations on your amazing achievement; I can scarcely even begin to comprehend that kind of energy...
Perhaps it's time to consider a turret mount?... ;)
Jesse
-
Thanks guys,
That was an excellent point with the recoil Bob, didn't think about the airmass and it's affecting recoil.
Yes 338 lapua is similar on energy but the momentum of the projectile is dwarfed by the 20mm slug. Can hit steel with .338 and it makes a ringing sound and swinging some.
Hit it with the 130 gram projectile and you'll be searching the plate from the range and sometimes from pretty far.
8mm 200mm round plate flys 20-40m depending on the rigging. Usually a conveyor belt or car timing belt.
Not going to push this much more, the forces are starting to be more than the materials and O rings can handle dynamic load.
Starting to be material choices like Nasa shuttles. fiber reinforced PEEK, 7075, 42crmo4, GR5 titanium and molybdenum ceramic friction reduction coatings.
FEM analysis starting to be a must on design and material choices. So don't try this at home, if you don't know what you are doing.
Valve parts have a short lifespan, I don't think the Peek seal lasts more than 200-300 shots, and O rings less than that.
Just something to think about.
Marko
Edit: couple of pictures
(https://i.ibb.co/1J1zWtb/A91-F4-C55-C18-F-474-F-B8-D4-49328-C2-FD87-B.png) (https://ibb.co/qFKJQ3x)
(https://i.ibb.co/6Pwb7Tf/D41-F5061-37-E6-462-F-9914-ADDF8-E58-EBE2.png) (https://ibb.co/Phj4vPf)
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How far can the LabRadar track those massive slugs?....
Yes, at the power levels you are running, the air mass will be approaching the slug mass.... That is one of the reasons 50% of maximum is so difficult to achieve.... but easier with heavy slugs travelling slowly.... It is also the main reason that Helium can increase the performance, it only has 1/7th the density of air, so for the same push (pressure), there is much less gas mass to accelerate, and more of the energy goes into the bullet.... ;)
Bob
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It was set to 100m and it tracks to that distance fine. We unfortunately have the EU version with crippled power output.
Would be fun to track the projectiles further out.
Marko
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Just amazes me every time this thread pops up. What an amazing build Marko! WOW.
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Not going to push this much more, the forces are starting to be more than the materials and O rings can handle dynamic load.
I think the benchmark has been set high enough, truly an amazing project.
I would be tempted to play with projectile options, with that kind of energy available a smoothbore barrel, perhaps somewhat larger caliber, would give some interesting possibilities for impressive loads of buckshot or perhaps even APFSDS style darts if you want to go for some penetration records:
https://youtu.be/0giK-zqrAKI
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Thanks guys,
And Jack don't you go and give me more ideas to try. ;D
Interesting idea nonetheless.
Marko
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For more power please look up light gas guns!
https://duckduckgo.com/?q=light+gas+guns&t=ffsb&ia=web (https://duckduckgo.com/?q=light+gas+guns&t=ffsb&ia=web)
https://www.nasa.gov/centers/wstf/site_tour/remote_hypervelocity_test_laboratory/two_stage_light_gas_guns.html (https://www.nasa.gov/centers/wstf/site_tour/remote_hypervelocity_test_laboratory/two_stage_light_gas_guns.html)
That will drop your jaw.
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Yes, they are cool, but they start with an explosion to propel the piston.... so not an airgun.... You want pure power, look at long range artillery, eg. Naval guns, etc....
Now back to airguns.... ::)
Bob
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Marko , whats the max fpe where the valve is still reliable longer term? im guessing youre still figuring this out .
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I would say something around 2500fpe is reliable on peek poppet and steel stem and 3000fpe with titanium stem 7075T6 poppet and better grade o-rings and stuff.
Beyond that it's starting to consume parts, O-rings, poppet seals and so on.
Video editing is about done, should be uploading today or tomorrow.
The valve actuation is very fast and all the dynamic forces in the system seems to kill parts.
Don't really care if the gun only lasts for some hundred shots, it's not like I shoot it every day anyways.
You'll see it in the video how pleasant it is to shoot.
It's like Carl said, when you touch that puppy off you'll feel the love. ;D
Marko
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Yes, they are cool, but they start with an explosion to propel the piston.... so not an airgun.... You want pure power, look at long range artillery, eg. Naval guns, etc....
Now back to airguns.... ::)
Bob
Then please state PCP airguns as purely gas release (and not gas assisted in any way or form) , and state that as a rule in here!
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The most powerful air rifle on the planet.
https://youtu.be/1jTnrjVxtVo (https://youtu.be/1jTnrjVxtVo)
Marko
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Wow that has some kick to it.
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Ouch!
That thing kicks like a mule.
Dave
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Excellent work Marko! 8)
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amazing gun, congratulations Marko
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Thanks guys
Yes it sure does kick hard, 50bmg feels mild in comparison.
But gun like this should bruise you up a little. ;D
Marko
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That is one impressive airgun Marko! I love how calm you remained and were when you told your buddy "that was something broke". I had to chuckle a little.
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What do you use to swage your large bore projectiles? I'm struggling with a lee single stage trying to manufacture a reliable swage for my Zeus, (.729). any input would be appreciated.
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Watching those water jugs just disintegrate-WOW!!
Looked like you could get whiplash shooting that thing!!! :o :o
Jesse
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What do you use to swage your large bore projectiles? I'm struggling with a lee single stage trying to manufacture a reliable swage for my Zeus, (.729). any input would be appreciated.
I use hydraulic press to calibrate the slugs, mold drops around 20.8mm and calibrate to 20.4mm on single press on custom made die. Tried with reloading press and was afraid to brake it before anything happens.
Marko
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Watching those water jugs just disintegrate-WOW!!
Looked like you could get whiplash shooting that thing!!! :o :o
Jesse
That was awesome shot, we have more camera angles on that for the longer video.
The truth is my neck is sore next day after the shooting, and wrist and shoulder too.
It's not the most pleasant gun to shoot but the impact on targets is worth little pain.
Marko
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That is one impressive airgun Marko! I love how calm you remained and were when you told your buddy "that was something broke". I had to chuckle a little.
Thanks,
After history of drag racing and building engines for racing you get used of stuff happening when pushing the envelope. No point loosing your cool about it, it's already broken.
After all failure is a learning experience, you get to build it better.
Marko
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Oh so very true sir.
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So had some time to fix the rifle, balancer cylinder broke in two as valve buffer broke and the valve bottomed out on the cylinder head.
All is fixed and made a slight modification to prevent that from repeating.
Marko
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Looking forward to some more videos. That thing is awesome!
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Thanks Chris,
We will shoot some video next weekend, have stuff to shoot at, old helmet, harddrives etc..
Marko
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Looking forward to seeing the vids !
Dave
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Lets start by adding a statement to this, ALWAYS WEAR SAFETY GOOGLES!
Now that is out of the way, and yes I did wear mine. And that saved my eye for sure.
I have not been a fan of the two lever guns, bolt and separate cocking handle. It's an accident waiting to happen, and so it did happen.
7mm steel safety pin on the bolt sheared clean off, and sealhead and O ring was gone somewhere.
(https://i.ibb.co/TwSDvjt/020-A2-F5-A-A37-A-4696-82-FF-D0-E8-B45-D92-B0.jpg) (https://ibb.co/WHwNx8f)
What happened is I effed up somehow, cocked the hammer and at that point always secure the bolt with my thumb while holding the cocking lever. Just a routine to make sure it's locked.
But this time I noticed that I forgot my safety's and reached out to grab them from the table.
Either my hand hit the bolt handle and accidentally opened it or I didn't close it. No matter what but routine was disrupted and the bolt was not locked all the way or was completely open when I pulled the trigger.
Reconstructed picture after the shot.
(https://i.ibb.co/GRDwr1m/E6036-AEC-79-C3-40-BF-A2-F9-81437-C2-D2475.jpg) (https://ibb.co/m4KsPYp)
That Tikka cheek rest and safety pin saved my head, it directed the bolt down and slowed it enough that I only have a bruised cheek and got a mild concussion. Felt like being hit in the head with a heavy fist.
Every failure you walk away from is a learning experience, and I won't be shooting the rifle before it is modified so that it is impossible to actuate the valve when the breech is not fully locked.
I have feared what would happen if this freak accident of discharging the gun with the bolt open happens but thought that I'm careful enough always... clearly I was wrong, and it just takes that one split second disruption in your routine.
So stay safe and always wear the glasses, and be mindful of the danger of big bore airguns.
Marko
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I’m glad you’re ok! Whew, bet that was scary.
Thanks for sharing, keeps us all humble.
Dave
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Yikes - the way that stock piece trapped the bolt is a small miracle. Or maybe it reflects your choice of durable materials…
Been checking this thread every time it updates - what a great project.
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Glad your okay. That's some scary stuff right there. I applaud your tenacity and humility Marko. Thanks for sharing.
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YIKES!!!! :o :o :o
Glad you're OK, sure reminds you to keep those layers of redundancy in whatever you're doing! :-\
Jesse
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thank god youre okay! thats some serious force trying to eject the bolt.
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Thanks guys,
There is some risks involved when pushing the boundaries, but when stuff starts to get downright dangerous it's time to rethink and redesign the system.
Can't rely on the human factor, needs to be foolproof it seems. Have made some things that way so I don't trust anyone else to operate them but it seems it includes myself too.
Well season is about over in the north amongst penguins and polar bears or what ever people thinks walks in here. Fall is here and shooting will about stop for the winter.
We will post some video of the fun from weekend. How many 4-5 liter water jugs it takes to stop a 20mm airgun? It takes about four to stop a fifty cal BP as the bullet shatters on impact.
Marko
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Sounds like your going to have some drawing board time. Good luck.
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Scary, good to hear that you are OK - it could have been much worse.
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Glad to hear you are OK, Marko!.... It's not the static pressure you have to worry about with a bolt, it is the momentum the bolt has after accelerating backward until the air vents and the pressure drops (over 100mm, by the looks of it).... Lloyd did a great study on this, and the strength of the shear pin required on your Monster would be considerable.... Certainly a 7mm pin doesn't come close, if the gun has any possibility of being fired without the bolt being locked down.... A learning experience for sure.... :o
Bob
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It was propably the best possible outcome from insident like that you can imagine.
So many details where you were lucky.
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At some power level implementing a disconnector seems like a great idea. A mechanical switch, interrupt or block that prevents firing, if the bolt is not fully closed and locked. Standard on most PBs.
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Long winter to make changes.
I uploaded short video on YT of season ending fun.
https://youtu.be/2gV1hbrMFpM (https://youtu.be/2gV1hbrMFpM)
Marko
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Good thing you specified that the frying pan was non-stick ;D
Truly impressive effect on target, particularly the hydrostatic shock from the melon and jugs on the chair and table structure respectively. That incompressible fluid is transmitting a lot of power.
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Daaang.... ;D ;D ;D
8)
Jesse
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8)
Good stuff,
Dave
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Thanks guys.
Was pretty impressed myself about the slug passing 7 canisters of water. Guessed it would stop on the fifth or something but noup.
Now it's snow here and everything grinds to a halt for the winter.
Need to think what next, is there any more to be had on this platform. Probably projectile development if something, some armor piercing sabot rounds or something.
Marko
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Lets kick this up, finally had some time to make changes to the safety of the gun, by adding safety.
8mm steel safety pin that has a cutout for the hammer.
Hammer moves only 2mm if safety engaged.
(https://img.aijaa.com/m/00664/15159728.jpg) (https://aijaa.com/F0DUHP)
Really need to take the safety off and wont came off by accident.
Marko
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Nice, is that switch taken from an existing gun?
It struck me while testing the other day that one would need to fire a hundred shots from a relatively high powered 0.22" air rifle to get the same FPE as a single shot from this beast, truly impressive and you certainly don't want it going off by accident!
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Yes you are correct, it's from a QB trigger group.
Just too lazy to make a small part like that.
Marko