GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Motorhead on February 12, 2020, 05:21:05 PM
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8) This was a fun project that has been in the works for well over 2+ years now.
After recently having a gracious GTA member do the final machining on the main air tube, all the parts and pieces stashed away could get assembled. Into the mix some modern Tech as well making for a rifle that LOOKS LIKE an M-rod but ONLY used 3 OEM parts :o Those being a partial & re-machined steel Air tube, Trigger group and Stock. EVERY OTHER PART is something custom or one off exotic / prototype.
Inside this beast sits one of my custom balance valves ( actually this one ) with the reversed thimble & external spring. Transfer port is a TAPERED design reducing the output end for increased throat back pressure and faster poppet closing. * tested & proven effective in a previous thread.
Hammer is a buffer type of my own design having an adjustable peek striker thrown at the valve via an External SSG devise where screw protrudes out the back of adjuster when cocked.
Air tube at a length providing @ 80 cc of plenum then a WAR drop block. 500cc 3K aluminum tank with a prototype adjustable output regulator provides the required HPA.
Up on the upper receiver sits a JSAR side lever breech with a full length @ 23.7" LW Poly barrel in .25 caliber. Custom shroud, end cap screwing on placing the assembly into tension being Super stiff and no wiggle !
Stock was cut out as needed for the regulator and kept long on the right side, shortened on the left for gauge & adjustment access. All done painted in Rustoleum textured along with shroud tube.
There the build in condensed format ... performance data to follow :o
Scott S
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Oh Boy Scott that's my type of Marauder! Can't wait to see how it shoots and all the data. Very, very awesome.
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Performance wise it took a bit of trial & error in getting the hammer strike correct in not only stroke but hammer weight. The buffering aspect of hammer while not active keeps the valve lift in check providing a few more shots off reg without valve over dwelling. Total hammer weight @ 37 grams and stroke @ 3/16" less than OEM spec maximum.
This rifle was conceived and set up to be a Pellet shooter leaving the slug duty to my WarP .22 ( Another thread ) In my extensive testing with the LW Poly not only were JSB 25.4 Kings happy at +/- 1000 fps from it, the Benjamin 28 grains were too at 960/970 with JSB 34's trucking along in the upper 800's. This on 2000 psi set pressure leaving me with 1000 psi to play with on the 500cc tank.
Here is where rubber meets and road sort of speak .... Having a very blended array or technologies many of us have seen these past couple years, some fortunate to work with ;) has been married into this build with the results being pretty darn astounding IMO.
As you see the gun with the spec parts mentioned, shooting the Benjamin 28 grain dome pellet at @ 960/970 fps guns cruising along at an easy 58 ft-lbs. Accuracy at 80 yards is inside a QUARTER coins group if I'm doing my part. ( not going to share groups or entertain such look at this silliness )
Last full tank string of shots taken started at 3000 psi and after @ 62 shots both gauges were at 2K and just showing movement lower. * So were seeing 62 shots on 1000 psi off a 500cc bottle.
The numbers using Lloyds calculator has it at: avg FPE/cuin per shot 1.72 with avg PSI used per shot 16
Damnnnn I'll take that too the bank any day, any where !!
As too if or not there is more power available ??? .... ABSOLUTELY being just a matter of pressure increases and adjusting hammer strike to match.
Well now I know I've built a worthy platform that with a barrel swap to unchoked could, would be an AWESOME slugger ... or just leave it be as the SLEEPER it appears to be 8)
Thanks for following along,
Scott S
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yer killing me...... :)
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I do love those LW polygon barrels. And bottle marauders...:) next up is a hot 30 cal pellet shooter; the one in 44" twist, 3-groove should be ready shortly.
Try putting a screw in the mag well to tie down the middle of the breech to the air tube. The pressure of the firing pulse tries to bend the breech into a banana. Thread the tube, and clearance the valve just a wee bit.
cheers,
Douglas
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Most excellent build!!!
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Try putting a screw in the mag well to tie down the middle of the breech to the air tube. The pressure of the firing pulse tries to bend the breech into a banana. Thread the tube, and clearance the valve just a wee bit.
cheers,
Douglas
Beauty of the JSAR breech is it is @ 1/4"+ taller with the extra material thickening the web under the mag slot where the bend could happen ;)
OEM M-rods have a 7/8" shroud and my gun as shown is sporting a 1" and still has @1/8" gap between it and air tube. * Much beefier breech.
Good point tho for a stock breech big HP .30 cal for sure !!
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Motorauder
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Examine a close-up of the Raptor...it has just such a screw...:)
cheers,
Douglas
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Examine a close-up of the Raptor...it has just such a screw...:)
cheers,
Douglas
Indeed ... made note of such while assembling them for JSAR.
good mod indeed, tho IMO more needed with a Rapor than a M-rod due to there use of small fine thread pitch screws
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Wow. I wonder what shot count would be if you lowered Kings to 880-900?
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Wow. I wonder what shot count would be if you lowered Kings to 880-900?
LOTS.
Scott, one impressive build. Seeing all the new tech in such a platform and delivering it at such an efficiency level is just mindblowing.
So the next step: monetize and provide a Motorauder build kit :)
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Scott, wonderful build! You sure have the talent and knowledge to put that together 👍.
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Scott,
Looks like it was worth a 2 year effort. You certainly can't buy anything like that. Performance sounds super.
I did have a little chuckle when you said in the first post that it only has 3 OEM parts. Some people might say that is a sign of an obsessed sick mind, but I call it creativity!
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Scott,
Looks like it was worth a 2 year effort. You certainly can't buy anything like that. Performance sounds super.
I did have a little chuckle when you said in the first post that it only has 3 OEM parts. Some people might say that is a sign of an obsessed sick mind, but I call it creativity!
I suspect it is more; there are more than three pieces in a trigger group.
cheers,
Douglas
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Scott,
Looks like it was worth a 2 year effort. You certainly can't buy anything like that. Performance sounds super.
I did have a little chuckle when you said in the first post that it only has 3 OEM parts. Some people might say that is a sign of an obsessed sick mind, but I call it creativity!
I suspect it is more; there are more than three pieces in a trigger group.
cheers,
Douglas
Lol ... seriously you buy it as an assembly and it attaches as such.
But if you wish to be nit-picky so be it.
Douglas your too much ;D
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Reminds me of my Brod, where the only factory part at all is the trigger group. It's not really a Marauder at all at that point is it? ;D
Nice work!
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Motorauder
Lol. +1 the man, the legend. Finally a correctly built Marauder.
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I REALLY like the Tan Rustoleum Bed Liner paint job!
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Big Thumbs Up...Your The Man
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A well thought out and executed AG in it's finesse. well done Mr. Scott! 8)
Knife
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Motorauder
Lol. +1 the man, the legend. Finally a correctly built Marauder.
So, Scott is calling this a "sleeper", and I'm looking at it and my first thought is that it just looks down right mean.
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Been a spell and in the past month had a chance to stretch it's legs seeing what it's got ?
Set up as originally shown had a chance to shoot it on paper @ 115 yards using JSB King Heavies ( 34 grains ) finding it capable of @ 1 1/2" groups in 8-12 mph wind. Day we shot the wind was present and we just never got to really drop em on top of one another. Group I was with gave a nod of approval being it was out shooting there FX Impacts in .22 cal shooting 25 grain heavies. As set the power was hovering at @ 60 ft-lbs.
Fun project to build and fun to shoot ... just got no real practical use for a .25 cal other than s*&^s and giggles shooting ???
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Yep, not really useful for you at all. You should pack it up and-------! ;D
After all , you know how much I love a Bottle Gun. ;) + 8)
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Another amazing build Scott!
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“ Fun project to build and fun to shoot ... just got no real practical use for a .25 cal other than s*&^s and giggles shooting ??? ”
What about Belding Ground Squiirels????
When a .25 hits them the sound is spectacular..
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8) This was a fun project that has been in the works for well over 2+ years now.
After recently having a gracious GTA member do the final machining on the main air tube, all the parts and pieces stashed away could get assembled. Into the mix some modern Tech as well making for a rifle that LOOKS LIKE an M-rod but ONLY used 3 OEM parts :o Those being a partial & re-machined steel Air tube, Trigger group and Stock. EVERY OTHER PART is something custom or one off exotic / prototype.
Inside this beast sits one of my custom balance valves ( actually this one ) with the reversed thimble & external spring. Transfer port is a TAPERED design reducing the output end for increased throat back pressure and faster poppet closing. * tested & proven effective in a previous thread.
Hammer is a buffer type of my own design having an adjustable peek striker thrown at the valve via an External SSG devise where screw protrudes out the back of adjuster when cocked.
Air tube at a length providing @ 80 cc of plenum then a WAR drop block. 500cc 3K aluminum tank with a prototype adjustable output regulator provides the required HPA.
Up on the upper receiver sits a JSAR side lever breech with a full length @ 23.7" LW Poly barrel in .25 caliber. Custom shroud, end cap screwing on placing the assembly into tension being Super stiff and no wiggle !
Stock was cut out as needed for the regulator and kept long on the right side, shortened on the left for gauge & adjustment access. All done painted in Rustoleum textured along with shroud tube.
There the build in condensed format ... performance data to follow :o
Scott S
The ship of Theseus paradox, ala Airguns. I love it!
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Well time for an update after @ 4 1/2 months of barrel/caliber swaps, valve & hammer tweaks etc ....
Today no more screwing around with the smaller calibers in this monster having put back in the LW poly .25 we started with.
Last we were fooling with it the valve was back to a large balanced configuration, original hammer short stroked and tapered transfer port.
Adjustable regulators set point tho sitting on @ 2400 psi and we have a 480cc CF 4.5k bottle fitted now.
Get it sighted back in at 50 yards just to see how it shot ? ... Wow really really hard shooting both Kings and King heavies @ quarters diameter off shootin sticks and a stool. Too much recoil to be real steady, so likely more accurate than i was seeing.
CHRONY .... JSB 25.4 kings @ 1010 fps @ 57.5 ft lbs !! with the king heavy 33.95 @ 935 fps !! At a whopping 65.8 ft lbs power !!
Had figured early on just a matter of pressure to find more power ... Yea no shite !!
Scott
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So not only will it breathe fire, but it will breathe quite the long flame as well!
There was that one member in NorCal...I forget his name. Needed help on his farm/orchard to get rid of irrigation-chewing coyotes.
I'm thinking your exotic 'Rauder would make very short work of them. 8)
Impressive build!
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wow Scott, sounds like you tweaked it to perfection. i read somewhere on the internet, so you know it's true, that you're going to raffle it off to raise funds for your next project. wow! that sounds like a great idea! how much will a chance cost? i'll be 1st in line to buy!
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Just can't leave it alone striving to settle for a caliber and power setting that will shoot a wide variety of ammo well ???
Ended up settling for .22 caliber & using the HW 6 groove w/o choke being 24" long. This barrel just shoots so well over such broad speeds with both pellet / slugs it was the obvious best of the best choice.
Here is the breakdown on differing projectiles speed and power ;) ( 2150 psi set pressure )
Pellet JSB Monster Heavy 25.4 gr redesign @ 920 fps @ 47.7 fpe
Pellet H&N Barracuda 21.3 gr @ 1015 fps @ 48.7 fpe
Pellet JSB Heavy 18.1 gr @ 1070 fps @ 46.1 fpe
Pellet JSB Exact 15.9 gr @ 1120 fps @ 44.28 fpe
Pellet Crosman 14.3 gr @ 1147 fps @ 41.77 fpe
Slug NSA 24.8 gr @ 920 fps @ 46.6 fpe
Slug NSA 23 gr @ 948 fps @ 45.89 fpe
Slug NSA 20.3 gr @ 1008 fps @ 45.79 fpe
What i find interesting is that the power is so flat not really being dramatic with weight shifts as we see with conventional valved PCP's ???
No doubt with light stuff we see a dip, but in the upper weights there all within @ 3 fpe ... WOW be it a pellet or draggy in bore slug the power is there !!
As set now the muzzle report is very low being a dull thud and efficiency is appearing to be really really good.
Are we done yet ? .... Think we should be, REALLY I DO !!!
Scott S
Oups, spell correction
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Just can't leave it alone striving to settle for a caliber and power setting that will shoot a wide variety of ammo well ???
Ended up settling for .22 caliber & using the HW 6 groove w/o choke being 24" long. This barrel just shoots so well over such broad speeds with both pellet / slugs it was the obvious best of the best choice.
Here is the breakdown on differing projectiles speed and power ;) ( 2150 psi set pressure )
Pellet JSB Monster Heavy 25.4 gr redesign @ 920 fps @ 47.7 fpe
Pellet H&N Barracuda 21.3 gr @ 1015 fps @ 48.7 fpe
Pellet JSB Heavy 18.1 gr @ 1070 fps @ 46.1 fpe
Pellet JSB Exact 15.9 gr @ 1120 fps @ 44.28 fpe
Pellet Crosman 14.3 gr @ 1147 fps @ 41.77 fpe
Slug NSA 24.8 gr @ 920 fps @ 46.6 fpe
Slug NSA 23 gr @ 948 fps @ 45.89 fpe
Slug NSA 20.3 gr @ 1008 fps @ 45.79 fpe
What i find interesting is that the power is so flat not really being dramatic with weight shifts as we see with conventional valved PCP's ???
No doubt with light stuff we see a dip, but in the upper weights there all within @ 3 fpe ... WOW be it a pellet or draggy in bore slug the power is there !!
As set now the muzzle report is very low being a dull thud and efficiency is appearing to be really really good.
Are we done yet ? .... Think we should be, REALLY I DO !!!
Scott S
Oups, spell correction
Sweet results, extreme versatility. What more could one want out of a .22?