GTA
All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Topic started by: subscriber on January 21, 2019, 08:59:39 AM
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This thread is about the "bones" of a SSP rifle concept. It is unashamedly based on the cocking mechanism of the Baikal IZH MP-46M SSP pistol; except the rifle barrel would also function as the cocking lever. The rifle would have twice the swept volume; and twice the barrel length compared to the pistol; to achieve twice the FPE.
Baikal IZH MP-46M SSP pistol:
(https://www.pyramydair.com/images/zoomed/IZH-46M-Match-Pistol_IZH46M_pistol_zm.jpg)
(https://www.pyramydair.com/images/zoomed/IZH46M_6_zm.jpg)
SSP Rifle Concept:
Images with wood fore-end represent latest design; as at 23 January 2019. Includes reinforcing tube sections at front and rear ends of compression cylinder; and has barrel pivot location lowered, to improved strength of forward connecting rod at it mid-length "notch".
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=258168;image)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=258170;image)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=258172;image)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=258174;image)
Alternative fore-end cut:
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=258178;image)
{By the way; the long piston shown above and below, removes the need for a connecting rod with a "kink" in it. (See pistol design, with kinky connecting rod; linked below). Don't worry; the piston won't have a heavy solid body, like the one shown below. It will consist of a threaded rod with just the functional head and tail sections...}
Background:
I really like my Baikal IZH MP-46M SSP pistol. It is accurate, shoots hard for a target pistol; and above all, is very easy to cock.
Inspired by this pistol, I modeled its cocking mechanism in Solidworks. For the images in this thread about the SSP rifle to make sense, they should be viewed in the context of the 3D model of the pistol, and the analysis of the cocking dynamics given at this link: https://www.gatewaytoairguns.org/GTA/index.php?topic=153475.msg155688851#msg155688851 (https://www.gatewaytoairguns.org/GTA/index.php?topic=153475.msg155688851#msg155688851)
The IZH 46M pistol's fixed barrel and underlever cocking no doubt enable its accuracy. Its breech is reasonably accessible too. Now, rather than simply stretch all the parts, I elected to save weight by using the barrel as the cocking lever. The loading actions and breech access would be comparable with a break barrel springer.
I happen to have a 21" long 25 mm pneumatic actuator cylinder that could be re-purposed; so the design is based on that (but could obviously use something different) Thus, the barrel length in the concept shown below works with the available compression cylinder length; and should support cocking effort goals reasonably well.
The effective cocking lever length falls short of the 24", a doubled-up pistol would suggest. However, stretching the whole rifle length beyond a probable 34" overall length could make restore that cocking leverage, if required. This would require a longer compression cylinder (or chassis attached to the tube); and would enable a longer barrel than 2X compared to the pistol.
Side-lever cocking would have enabled the muzzle to overhang the front of the compression cylinder. However, due to the placement of the hinges, my design forces the muzzle to be back from the front of the air cylinder, and to pass through the cylinder to reach "full cock". This is a bit odd, and drives the shape of the short hooded frontal connecting rod.
Below are two shapes shown for this frontal connecting rod. The question is, which looks better? Or are they both hideous?
By the way, the muzzle end is the end near the hinges....
This is just a thought exercise at this point, but any comments are welcome.
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More...
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Long nose...
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Which has a better looking "muzzle end"?
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=257716;image)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=257728;image)
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Edited original post; above. Added images with wood fore-end to represent latest design; as at 23 January 2019.
Also added reinforcing tube sections at front and rear ends of compression cylinder. Barrel pivot location has been lowered, to improved strength of forward connecting rod at it mid-length "notch". Over-center geometry of piston when pressurized is unchanged.
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Not seeing any "wood". Am I missing something?
I like the lowered version better. Just looks more streamlined, less "Russian", haha.
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Not seeing any "wood". Am I missing something?
Not seeing wood in this image?
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=153749.0;attach=258178;image)
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Very cool!!
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Ahh.....I didn't look far enough upward in the thread. You did say "edit original post" but I worked late last night, so....
Anyway, the one I thought looked less Russian is the lower pic of the pair above (non wood pics). The barrel sitting more snugly to the pump tube and the front slope of the barrel "hood" just looks better to me.
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Peter, do you see this as a way to get an SSP up into higher MV's? Given the greater leverage you'd have with a longer barrel (than say a 46M's cocking lever) you could increase the swept area and realize a gain in power.
Now that would be a nice alternative to PCP's or multi-pumps. And shoot a lot smoother than a break barrel springer.
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id go overkill on the barrel diameter or add some " spine " to it.. depending on the bore size of the piston i like the layout.. ( we previously discussed an extended p17 last yr )
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Peter, do you see this as a way to get an SSP up into higher MV's? Given the greater leverage you'd have with a longer barrel (than say a 46M's cocking lever) you could increase the swept area and realize a gain in power.
Now that would be a nice alternative to PCP's or multi-pumps. And shoot a lot smoother than a break barrel springer.
In a nutshell; exactly.
Double the swept volume, double the barrel length; for double the expansion ratio and double the leverage.
So twice the FPE of the pistol, for the same peak cocking force; gained via the longer stroke, and greater leverage.
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Peter, do you see this as a way to get an SSP up into higher MV's? Given the greater leverage you'd have with a longer barrel (than say a 46M's cocking lever) you could increase the swept area and realize a gain in power.
Now that would be a nice alternative to PCP's or multi-pumps. And shoot a lot smoother than a break barrel springer.
In a nutshell; exactly.
Double the swept volume, double the barrel length; for double the expansion ratio and double the leverage.
So twice the FPE of the pistol, for the same peak cocking force; gained via the longer stroke, and greater leverage.
VERY COOL!!
So when are you sending me the prototype for testing? :P
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id go overkill on the barrel diameter or add some " spine " to it.. depending on the bore size of the piston i like the layout.. ( we previously discussed an extended p17 last yr )
I am planning to massage the design to accommodate a 3/4" shrouded barrel. That said, if you look at the whimpy cocking arm section on the piston, the barrel in my 1/2" OD design is much stronger in bending to carry the same peak force, despite the increase in length.
At this point, the plan is to make this device in .177. The pistol achieves a maximum velocity of 495 FPS with 7.4 grain pellets, and a maximum of 4.25 ft.lb with 10.34 grain pellets. An 8 ft.lb rifle would put it in the same class as a hot shooting HW30. I may try to boost the stroke length a little, but the overall length of and weight of the rifle would suffer, it taken too far.
Right now, the overall length would be about 36" with a 14" length of pull stock. I think that exceeding 40" would completely spoil the result, assuming it could be done. Else, 12 ft.lb may be possible. The thing is that simply tripling the swept volume of the pistol will not yield thee times the FPE. Not unless the efficiency stayed the same. I am convinced that the way to achieve this would be to keep the compression volume the same, such that the peak pressure nearly triples. That would triple the peak cocking force, unless the barrel were three times as long...
I might consider a bullpup configuration to keep things short, but would prefer something that has a look and feel closer to an HW50.
I tried cocking a "30 lb peak cocking force" gas ram "springer" upside down, to simulate the barrel cocking lever ergonomics of this SSP rifle. I can't do it. So, I really do not want to go much over a peak cocking force of 20 lb at any barrel length. Either that, or I need to make this a fixed barrel SSP, with under-lever or side-lever cocking... Somehow, cocking in the normal springer break-barrel direction, my point of objection is much higher than 30 lb. Just not "upside down". Maybe I need to swap hands, or something :)
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So when are you sending me the prototype for testing? :P
Getting older is not as much fun as it is cracked up to be: My ability to imagine stuff only gets better, but my energy to actually produce parts keeps going down. One of the few things I miss about working for a large company, is having a crew that can help implement ideas; and carry them to completion...
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makes sense.. instead of machining each and every part. is there any way you could cannabilize some parts from a chinese springer ?? also dont overlook the load lower on the pivot end of the barrel.. if the peak pistol forces are double to triple , the forces at your hand might be reduced but that wont change the forces at the pivot point ( or close to the pivot point )
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makes sense.. instead of machining each and every part. is there any way you could cannabilize some parts from a chinese springer ??
I like the way you think. Am waiting for two 880 refurbs to arrive for that exact purpose...
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Am waiting for two 880 refurbs to arrive for that exact purpose...
the plot thickens.......
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ive painted myself into a corner before only to realize afterwards i could have used cheap factory made parts that are readily available lol
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Really cool idea.
I think it looks cool. I am OK with the barrel shorter than the powerplant/mechanism.
They both look good. Maybe do whatever configuration is easier to produce. If I help with review, can I get a deal on one?
Definitely looks like it would be a fun AG to own.
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Thanks for the enthusiasm, Sam. It is a long way before there will be hardware to pass out for evaluation.
I just got a phone call from a friend expecting some free design work, because she knows I can do it. Then, I can back to implementing the latest thinking about this SSP, to see if it represents an improvement...
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How do you plan to make the barrel steady enough while firing, some kind of a locking mechanism?
I imagine there might be slight accuracy or rather "precision" problems with that kind of construction, where the barrel is in direct connection with the piston via linkage. At least in my anschutz super air 2002 rifle there is noticeable vibration in the cocking lever while firing due to sudden pressure drop in front of the piston.
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Hi Albert,
Thanks for the design review questions:
The cocking lever (barrel) is actually completely unloaded, relative to the connecting rod in this design, when fully pressurized. See gap between anti-friction rollers and (barrel) cocking lever surface; indicated by red arrows in the attached images.
This is because the linkages carrying the air pressure load, are "over center"; pulling contact away from the barrel.
The air pressure loads are carried from the piston, via the long connecting rod, to the forward hoop shaped connecting rod (not the barrel cocking lever); ultimately, to the front hinge pin. The rear hinge pin does carry the vertical over center load component. That force tries to push the rear hinge pin down, as seen in the images below.
I envision V-block barrel beds, front and rear that would support the barrel when locked in the firing position. These blocks should be adjustable, so that slop can just be eliminated, without loading up and flexing the barrel. There should be enough clearance between the rear hinge and barrel support, that the V-blocks determine the barrel "in-battery" position. This is a detail that will take considerable thought.
The sights would be attached directly to the barrel; so no floating of the barrel relative to the sights; as can happen with a break barrel springer, having a scope on the compression tube.
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You could go .22....always wondered what one of these would make .22 and longer barrel
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Looks like a nice project. I like IZH pistols and rifles as well. I have a Walther LPM that uses a little more elegant multi leverage pump mechanism. You might want to check it out before you start constructing. It's a bit more powerful than the 46M and no more difficult to pump. Also, Parker Hale made a Dragon ssp rifle for hunting and FT in the 90s that was not too difficult to pump but had other issues. It was designed at 12 ft/lb. It was very robust. The pump was quite well designed but had a long stroke. Might give you some ideas for your current project if you can find a drawing or pictorial somewhere.
Bob
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Hi Bob,
Thanks for your interest and eagerness to help.
It seems the Walther LP1 is a refined Baikal MP46. Images below from: https://popgun.ru/viewtopic.php?t=140142
I have info on the Dragon. It is a pity that product died on the vine.
I have already managed to improve on the pump geometry I posted. However, I was advised by an industry rep not to post that here. Rather to apply for a provisional patent before any further disclosure. I have chosen to follow that advice.
Was hoping this thread would drop off the first page, but you revived it. So it would seem polite to reply, rather than to remain silent.
(https://popgun.ru/files/g/96/orig/410389.jpg)
(https://popgun.ru/files/g/96/orig/411414.jpg)
(https://popgun.ru/files/g/96/orig/410338.jpg)
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You would think that if a single pump ssp pistol can produce 580 fps that someone one would make a single pump rifle that would produce 780 to 900 fps even if it took 2 pumps . Who ever comes out with that gun is going to be rich . Even if it was only 780 fps it would sale like crazy . As far as I know the izh46m is the highest fps of any ssp ever made in a pistol . This rifle would have filled the bill but it was stopped for some reason . How stupid was that ? Something happened that it was stopped so fast . The cocking looked like the izh so maybe it was a patent problem . But someone need to make this gun . https://youtu.be/pJGKkL7vxy4
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You would think that if a single pump ssp pistol can produce 580 fps that someone one would make a single pump rifle that would produce 780 to 900 fps even if it took 2 pumps . Who ever comes out with that gun is going to be rich . Even if it was only 780 fps it would sale like crazy . As far as I know the izh46m is the highest fps of any ssp ever made in a pistol . This rifle would have filled the bill but it was stopped for some reason . How stupid was that ? Something happened that it was stopped so fast . The cocking looked like the izh so maybe it was a patent problem . But someone need to make this gun . https://youtu.be/pJGKkL7vxy4
For sure!!
I lucked out in getting a Baikal MP 532 rifle. It's the IZH 46M in a rifle version. Sorry, the only pic I have of mine is this one below.
It's the middle Blondie. I LOVE this rifle.
:D
(https://i.postimg.cc/7Y4GbBh6/HW30s-moderator-3.jpg)
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I know the 532 rifle was made for 10meters but I wonder if it could have made a gun that would at least be a 12 fpe gun for field target use .
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I know the 532 rifle was made for 10meters but I wonder if it could have made a gun that would at least be a 12 fpe gun for field target use .
Right. that would be nice, eh?
HEY, is that my Girlfriend in your avatar?
???
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You would think that if a single pump ssp pistol can produce 580 fps that someone one would make a single pump rifle that would produce 780 to 900 fps even if it took 2 pumps . Who ever comes out with that gun is going to be rich . Even if it was only 780 fps it would sale like crazy . As far as I know the izh46m is the highest fps of any ssp ever made in a pistol . This rifle would have filled the bill but it was stopped for some reason . How stupid was that ? Something happened that it was stopped so fast . The cocking looked like the izh so maybe it was a patent problem . But someone need to make this gun . https://youtu.be/pJGKkL7vxy4
^
This.
Maybe the market isn’t broad enough?
But I think a SSP with ~12fpe and 10meter gun type accuracy would be such a cool backyard pigeon and squirrel gun.
I understand springers are close enough.
I understand MSPs are close enough.
I usually shoot springers.
But this type of gun would be such a cool and unique gun to own and pass down.
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rws45user,
I think cheap PCPs killed all the expensive 12 FPE SSP rifles.
I was working on a design for one, when advised by an industry rep not to share that on open forum. That it should be developed and sold to an airgun manufacturer. Covid-19 interfered with showing hardware to a particular manufacturer by the rep.
Apart from that particular design, I am working on a concept that looks and cocks like a break-barrel springer, but shoots like a SSP.
Rather than trying to push down the coking lever, the barrel would be pulled down and back, with the same very natural feeling ergonomics as a common break-barrel springer. The rest of the mechanism cannot be described without giving it away. My design may depart from what the target manufacturer is willing to build. Their rep also wants 12 FPE from a peak cocking force of 22 lb. I am trying to make that work.
My personal goals are 12 FPE from a single stroke, at a maximum of 30 lb cocking force. Like a detuned HW95. I started by stretching the MP46 pump mechanism. The designs I gave the rep looks nothing like that.
My break barrel design is even simpler. I am looking for an vibration free HW30 or HW50 like SSP that produces 10 to 12 FPE from one pump stroke. More from more strokes...
My biggest problem is that paying customers keep interrupting me with design work. :) Then, for fun, I do free designs, or try to find or generate useful info on this forum, to help fellow enthusiasts. I want to get back to my SSP rifle concept to explore the next design approach. This after meeting and running along a wall like a rat for, a few months, trying to find the holy grail...
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I know the 532 rifle was made for 10meters but I wonder if it could have made a gun that would at least be a 12 fpe gun for field target use .
Right. that would be nice, eh?
HEY, is that my Girlfriend in your avatar?
???
My ex ;D
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rws45user,
I think cheap PCPs killed all the expensive 12 FPE SSP rifles.
I was working on a design for one, when advised by an industry rep not to share that on open forum. That it should be developed and sold to an airgun manufacturer. Covid-19 interfered with showing hardware to a particular manufacturer by the rep.
Apart from that particular design, I am working on a concept that looks and cocks like a break-barrel springer, but shoots like a SSP.
Rather than trying to push down the coking lever, the barrel would be pulled down and back, with the same very natural feeling ergonomics as a common break-barrel springer. The rest of the mechanism cannot be described without giving it away. My design may depart from what the target manufacturer is willing to build. Their rep also wants 12 FPE from a peak cocking force of 22 lb. I am trying to make that work.
My personal goals are 12 FPE from a single stroke, at a maximum of 30 lb cocking force. Like a detuned HW95. I started by stretching the MP46 pump mechanism. The designs I gave the rep looks nothing like that.
My break barrel design is even simpler. I am looking for an vibration free HW30 or HW50 like SSP that produces 10 to 12 FPE from one pump stroke. More from more strokes...
My biggest problem is that paying customers keep interrupting me with design work. :) Then, for fun, I do free designs, or try to find or generate useful info on this forum, to help fellow enthusiasts. I want to get back to my SSP rifle concept to explore the next design approach. This after meeting and running along a wall like a rat for, a few months, trying to find the holy grail...
have you thought about using xometry or protolabs to to get some proto parts made ?
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have you thought about using xometry or protolabs to to get some proto parts made ?
I have used both on other projects. They are fast, but very expensive. Even their CNC machining is not very accurate. You need to finish cut important dimensions yourself. So, if you want to make a compression cylinder, forget about them creating a round cylindrical ID, of the right diameter and internal finish. You are better off doing it yourself.
I would be careful what I let them make. They have language about not making certain parts, and probably have someone on the lookout for anything resembling such.
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have you thought about using xometry or protolabs to to get some proto parts made ?
I have used both on other projects. They are fast, but very expensive. Even their CNC machining is not very accurate. You need to finish cut important dimensions yourself. So, if you want to make a compression cylinder, forget about them creating a round cylindrical ID, of the right diameter and internal finish. You are better off doing it yourself.
I would be careful what I let them make. They have language about not making certain parts, and probably have someone on the lookout for anything resembling such.
i used xometry and was happy with the parts.. granted , i didnt need anything beyond .005 accuracy.. Were i making a compression cyclinder, id be nervous also.
Yes , i sent a picitanny rail into their program for Quote, REJECTED lol..
Theyre extremely expensive for 1 or 2 parts, and luck plays a role because they can use different shops each time.. thankfully i was ordering 40 parts so it was reasonable costs
aside from that , im wondering if in 2021 the large airgun manufacturers see a market in ssp ?? and whats the goal price point .. I love the idea of ssp but see a limited market with econo pcps .
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My price goal for a SSP rifle, that looks, feels and shoots like a HW 30 or 50; would be to sell it at that same price as those springers. Of course, if one sold the design, the manufacturer and distributor would sell it at whatever they think they can get. The AV 46M was selling for $600. That is a nice way to put costumers off. Especially if it does not work as well as the Izzy version.
Rather than make a target rifle, my goal is to make a sporter / plinker that is easier to hit with than the equivalent springer. Just because something is new, different or scarce, does not mean it is very good. It needs to be good enough, and much easier to extract that potential than a springer. Also, none of the spiky cocking force of even something like the wimpy Daisy 753 or Beeman P17. So, good value for money and user friendly; rather than a $2000 target rifle.
Anyway, this thread was dormant, until someone woke me up :)
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Hi All, I don't think you need to stress over the compression chamber. I used Plymouth brand chromoly tubing, it has a very smooth finish on the inside.
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Hi All, I don't think you need to stress over the compression chamber. I used Plymouth brand chromoly tubing, it has a very smooth finish on the inside.
that was for the 12fpe ssp correct ?
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Hi Rob, Yes, I order the tubing from Air Parts Inc. (air craft supplies) and request the Plymouth brand. There's a wide selection of sizes.
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I often wondered why this was never done also as it would be a brilliant idea for an air rifle. No recoil, no gas and no multi pumping to get to a reasonable power for close range vermin. Also if the pistols were so successful and proven, why should this be such a problem...and never taken up by a manufacturer..
There is a scientific reason....
If you increase a pneumatic cylinder by twice its size ..in any industry, not just the world of airguns...you increase the required force to pressure it by 4 x...The cube rule of pneumatic pressure.
If you run the math on this, It can start to add up to some really alarming pressures, both in pressure and sealing. Which is why multi pumping, in tiny steps of pressure gets selected.
Bowkett produced one ...just a small run, cottage industry style in the late 80s but it was dropped. The seals were prone to scorching and the cocking effort massive. Even with the biggest lever ever fitted to an airgun it still took 35lbs of force to work it, wearing out the major pivot pin in short order.
Such a massive quantity of air, being forced into its tiny resevoir in one go, burnt the seal out after about 200 shots and the gun required stripping...I think 200 were made and it was dropped.
All is not lost however.
I once stuck a .22 barrel on a 46m and got in excess of 400 fps, perfectly acceptable for a garden ratting gun.
A friend of mine also added a 16 inch barrel to a .177 and made a rifle stock for it. I am not certain but think it was doing about 550 fps if memory serves me right...
As a point of interest, i once added a piece of Crosman barrel to a HW75 running it to the true muzzle, which is recessed by 1.5 inches (The actual barrel is only 6.75 inches) and picked up another 35 fps. Anyone can perform this mod with access to a lathe, by cutting a 1377 barrel down just infront of where the TP hole is. Found the Crosman barrel more forgiving on pellets too.
A 440 fps HW75....never did get around to trying one in .22
I often wondered why HW did not run the barrel to the true muzzle on this gun, especially with Beeman demanding good power from the design...stupid really but it does make the HW75 a better platform for such work than any other model available as they all have barrels running full length.
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Hi All, I don't think you need to stress over the compression chamber. I used Plymouth brand chromoly tubing, it has a very smooth finish on the inside.
Thanks James. Seamless tubing is perfect: https://www.plymouth.com/products/promoly-seamless-4130-steel-tubing/ (https://www.plymouth.com/products/promoly-seamless-4130-steel-tubing/)
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Interesting history lesson, Steve
I was going to say that the problem was that compressing air to store energy for pneumatic airguns, is the poor efficiency: To use highfalutin words; the heat of compression is rejected. That represents wasted energy. Energy that does significant useful work when the airgun is a "springer".
I walk up the stair in my house and add over 2000 ft.lbs of gravitation potential energy to my body (while reducing my weight by 1 grain in the process :) ) It takes me about 10 seconds to to this, and I don't even notice the effort. Yet, using a hand pump to store enough air for 100 shots at 12 ft.lb (1200 ft.lb) in a PCP air tank is a real workout, taking me about 20 minutes.
So increasing efficiency is a must. The Paradigm used a booster spring to achieve this. There are other ways.
If a PCP handpump can have the seals last, then a SSP's seals are no challenge by comparison. Even a muti-pump pneumatic is nothing compared to continuous pumping for a PCP. So, a SSP airgun company that cheaps out on the seals deserves to fail...
The bottom line is that you can specify a low cocking effort and "a lot of power", but you cannot achieve it without requiring a gorilla-like reach. My focus is on reducing the peak cocking force, while increasing the average force; within the comfortable ergonomic envelop possible for most potential customers.
Also, the air rifle must be light. I would rather have a 7 lb 10 ft.lb rifle, than a 12 lb 12 ft.lb rifle.
Rather than calculating the minimum wall thickness (with factor of safety applied) to contain perhaps 1500 PSI at the end of the stroke, and then use that tube wall thickness, my approach recognizes the spiky pressure profile of air compression, and reinforces a much thinner walled tube only near the high pressure end. Also at the bearing points.
Making simple hinges that can carry a few 1000 lb is not actually that big a challenge. It might be, if you use the wrong materials; or pins that are too small in diameter. The cost of 4130 is not that much more than mild steel. Hardened pins are a commodity. Close fitting bronze bushing can take huge loads, if sized correctly so that they have enough bearing area.
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I hope you can pull it off buddy...
I do not think it will be like the pumping of a hand pump, kn regard of scorching seals, but a huge pressure column being forced into a tiny on board valve...unlike what a hand pump has to do when charging an equally big cylinder of air with PCP....and achieved by many pumps do not forget.
However, you may have something...
Your idea to chase a more realistic energy of say 6-7 ftlbs could be key. I believed Bowkett and Parkerhale were chasing 10 ftlbs plus which was the problem. It was just too much pressure.
I am suprized however, that alternate barrels have not been more fully explored for the existing mechanism of the 46M ....I have tried to add the 16inch barrel version here...
Perhaps a simpler stock and the mentioned 550 fps would be adequate enough for you.
The standard barrel length in .22 got just above 400 fps ...perhaps a .22 16 inch barrel version?
For the record, I was usually getting approx 25 fps per inch with the couple of SSP I modified.
The 1.5 inches extra in the 75 giving 35 fps at 8.25 inches, for a total of 440 fps from 405 fps stock....with a decent 8 grain pellet.
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I am suprized however, that alternate barrels have not been more fully explored for the existing mechanism of the 46M ....I have tried to add the 16inch barrel version here...
Perhaps a simpler stock and the mentioned 550 fps would be adequate enough for you.
The standard barrel length in .22 got just above 400 fps ...perhaps a .22 16 inch barrel version?
For the record, I was usually getting approx 25 fps per inch with the couple of SSP I modified.
The 1.5 inches extra in the 75 giving 35 fps at 8.25 inches, for a total of 440 fps from 405 fps stock....with a decent 8 grain pellet.
My 46M generates 4 FPE at the muzzle with its stock 11" barrel, after I cranked up the compression setting. This is 495 FPS with a 7.4 grain pellet. If the gains you promote with a 16" barrel exist, then it should produce 495 + (5 x 25) = 6.3 FPE with the longer barrel. I seriously doubt that this will happen, because the velocity gained is actually not linear with barrel length. Because the pressure in the barrel keeps dropping as the expansion volume increases.
With such a low power airgun, pellet to barrel friction will easily dominate. Thus, velocity gains observed are more likely due to reduced barrel friction, than increased length. To prove this, start with a 16" barrel; test it, and lop off and inch at a time. Comparing a few different barrels and suggesting the velocity differences with them are due to the length differences are, shall we say; not scientific.
If every additional inch increased pellet velocity by 25 FPS, how long does a 46M barrel have to be to exceed 12 FPE? Never going to happen. Apart from adding a butt stock to my 46M, I have no interest in butchering it.
Unless its accuracy potential is retained, I really don't need it to shoot at 620 FPS. A long skinny barrel might look interesting to some. I think you will see more gains by increasing the input energy, rather than than by trying to improve system efficiency by means of barrel length only. To increase the input energy, you need a larger swept volume...
Consider that the Baikal factory made MP-532 rifle; using the same mechanism as the 46M shoots at the same velocity, despite its longer barrel:
https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-1/ (https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-1/)
https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-2/ (https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-2/)
https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-3/ (https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-3/)
Could owners of this 46M based rifle, hotrod the velocity? If so, do they? If not, why not...
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Phils and James 12 fpe ssp's have been very relaible as far as i know.. NO seal wear issues and James built his 10 yrs ago..I know both have moderate cocking effort , i believe phils was about 32 lbs ( seen here
https://www.youtube.com/watch?v=lPLllXu3L00&t=106s (https://www.youtube.com/watch?v=lPLllXu3L00&t=106s)
i think james had a bit higher cocking effort , he can comment hes already in this thread. seen here
https://www.tapatalk.com/groups/thegreencrosmanforum/here-is-james-perotti-s-ssp-pictures-stunning-t44499.html (https://www.tapatalk.com/groups/thegreencrosmanforum/here-is-james-perotti-s-ssp-pictures-stunning-t44499.html)
the challenges of SSP are what they appear to be , a large enough swept volume versus the mechanical ability to compress that volume in 1 stroke..
The major manufacturers could make a decent ssp tommorow if they decided , i think their trepidation is a good design thats reliable , and a solid market base.
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changing fundamentals of the linkage and where the peak force happens is the hold grail. LD had a radical idea a few yrs ago involving a 2 inch piston and a half stroke. ALL the compression would take place in the final 15 degrees of the arms arc.. Thus engaging the large piston when the M.a is at its peak.anyway , carry on ;)
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Thanks, Rob
Apart from the SSP build/s that you have done, there are actually quite a few out there. Some of them commercial. See samples below.
The point being that a 12 FPE SSP is not impossible. It may be that it is too expensive compared to PCPs, that are adjustable, and can produce much more power. As velocity sells, the convenience of a on board pump (that is not too heavy) is easily forgotten. Then, there are hybrids like the Millennium Pumper.
https://www.gatewaytoairguns.org/GTA/index.php?topic=156540.msg155730796#msg155730796 (https://www.gatewaytoairguns.org/GTA/index.php?topic=156540.msg155730796#msg155730796)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=156540.0;attach=266651;image)
https://www.gatewaytoairguns.org/GTA/index.php?topic=71647.msg682905#msg682905 (https://www.gatewaytoairguns.org/GTA/index.php?topic=71647.msg682905#msg682905)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=71647.0;attach=87576;image)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=71647.0;attach=87578;image)
https://www.gatewaytoairguns.org/GTA/index.php?topic=118868.msg1146392#msg1146392 (https://www.gatewaytoairguns.org/GTA/index.php?topic=118868.msg1146392#msg1146392)
https://youtu.be/Fdh06WhhQME (https://youtu.be/Fdh06WhhQME)
https://www.pyramydair.com/blog/2019/12/gamo-126-single-stroke-pneumatic-10-meter-target-rifle-part-1/ (https://www.pyramydair.com/blog/2019/12/gamo-126-single-stroke-pneumatic-10-meter-target-rifle-part-1/)
https://www.pyramydair.com/blog/2019/12/gamo-126-single-stroke-pneumatic-10-meter-target-rifle-part-2/ (https://www.pyramydair.com/blog/2019/12/gamo-126-single-stroke-pneumatic-10-meter-target-rifle-part-2/)
https://www.pyramydair.com/blog/2020/01/gamo-126-single-stroke-pneumatic-10-meter-target-rifle-part-3/ (https://www.pyramydair.com/blog/2020/01/gamo-126-single-stroke-pneumatic-10-meter-target-rifle-part-3/)
(https://www.pyramydair.com/blog/wp-content/uploads/2019/12/12-20-19-01-Gamo-126.jpg)
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My price goal for a SSP rifle, that looks, feels and shoots like a HW 30 or 50; would be to sell it at that same price as those springers. Of course, if one sold the design, the manufacturer and distributor would sell it at whatever they think they can get. The AV 46M was selling for $600. That is a nice way to put costumers off. Especially if it does not work as well as the Izzy version.
Rather than make a target rifle, my goal is to make a sporter / plinker that is easier to hit with than the equivalent springer. Just because something is new, different or scarce, does not mean it is very good. It needs to be good enough, and much easier to extract that potential than a springer. Also, none of the spiky cocking force of even something like the wimpy Daisy 753 or Beeman P17. So, good value for money and user friendly; rather than a $2000 target rifle.
Anyway, this thread was dormant, until someone woke me up :)
Hi Sub, just an FYI that way long ago, I had a SSP 12fpe rifle from Parker-Hale in the U.K. called the Dragon. Brilliant concept with a mechanically-advantaged looong single pump stroke that was relatively low effort and actually worked, but was eventually prone to leaks:
https://www.pyramydair.com/blog/2008/07/parker-hale-dragon/ (https://www.pyramydair.com/blog/2008/07/parker-hale-dragon/)
Sold it cheap to a buddy who was "gonna fix it" but I never heard of any success.
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Thanks Charlie,
Before I forget, the unusual blond plywood stocked SSP above, made by Ron (rgb1) achieves 20 ft.lb. It uses a "helper spring" system to maintain the air pressure during the shot cycle, similar to the Dragon in principle.
If you look at the date this thread was started; it was a long time ago. You should appreciate that the original intent and current strategy have diverged. Also; some of what I told you recently does not reflect the exact concept being offered to a particular airgun manufacturer. Nor where I think the market lies. Yet, I can't explain this in greater detail, because of an NDA I signed.
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My price goal for a SSP rifle, that looks, feels and shoots like a HW 30 or 50; would be to sell it at that same price as those springers. Of course, if one sold the design, the manufacturer and distributor would sell it at whatever they think they can get. The AV 46M was selling for $600. That is a nice way to put costumers off. Especially if it does not work as well as the Izzy version.
Rather than make a target rifle, my goal is to make a sporter / plinker that is easier to hit with than the equivalent springer. Just because something is new, different or scarce, does not mean it is very good. It needs to be good enough, and much easier to extract that potential than a springer. Also, none of the spiky cocking force of even something like the wimpy Daisy 753 or Beeman P17. So, good value for money and user friendly; rather than a $2000 target rifle.
Anyway, this thread was dormant, until someone woke me up :)
Hi Sub, just an FYI that way long ago, I had a SSP 12fpe rifle from Parker-Hale in the U.K. called the Dragon. Brilliant concept with a mechanically-advantaged looong single pump stroke that was relatively low effort and actually worked, but was eventually prone to leaks:
https://www.pyramydair.com/blog/2008/07/parker-hale-dragon/ (https://www.pyramydair.com/blog/2008/07/parker-hale-dragon/)
Sold it cheap to a buddy who was "gonna fix it" but I never heard of any success.
This is the Parkerhale rifle I mentioned above. Originally concept model was SSPR1 and later called the Dragon when they decided to risk a small production run. They built 200 units.
The lever does not look it in the picture shown but was 2ft long hence the realistic cocking effort of between 32lbs and 35lbs but it was found to over heat its seals. They experimented with higher grade O rings but i think they were largely unsuccessful before the gun was dropped.
John Bowkett made 2 different versions before selling his design to Parkerhale for production.
I am not doubting it can be done, jst concerned about reliability.
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I am suprized however, that alternate barrels have not been more fully explored for the existing mechanism of the 46M ....I have tried to add the 16inch barrel version here...
Perhaps a simpler stock and the mentioned 550 fps would be adequate enough for you.
The standard barrel length in .22 got just above 400 fps ...perhaps a .22 16 inch barrel version?
For the record, I was usually getting approx 25 fps per inch with the couple of SSP I modified.
The 1.5 inches extra in the 75 giving 35 fps at 8.25 inches, for a total of 440 fps from 405 fps stock....with a decent 8 grain pellet.
My 46M generates 4 FPE at the muzzle with its stock 11" barrel, after I cranked up the compression setting. This is 495 FPS with a 7.4 grain pellet. If the gains you promote with a 16" barrel exist, then it should produce 495 + (5 x 25) = 6.3 FPE with the longer barrel. I seriously doubt that this will happen, because the velocity gained is actually not linear with barrel length. Because the pressure in the barrel keeps dropping as the expansion volume increases.
With such a low power airgun, pellet to barrel friction will easily dominate. Thus, velocity gains observed are more likely due to reduced barrel friction, than increased length. To prove this, start with a 16" barrel; test it, and lop off and inch at a time. Comparing a few different barrels and suggesting the velocity differences with them are due to the length differences are, shall we say; not scientific.
If every additional inch increased pellet velocity by 25 FPS, how long does a 46M barrel have to be to exceed 12 FPE? Never going to happen. Apart from adding a butt stock to my 46M, I have no interest in butchering it.
Unless its accuracy potential is retained, I really don't need it to shoot at 620 FPS. A long skinny barrel might look interesting to some. I think you will see more gains by increasing the input energy, rather than than by trying to improve system efficiency by means of barrel length only. To increase the input energy, you need a larger swept volume...
Consider that the Baikal factory made MP-532 rifle; using the same mechanism as the 46M shoots at the same velocity, despite its longer barrel:
https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-1/ (https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-1/)
https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-2/ (https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-2/)
https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-3/ (https://www.pyramydair.com/blog/2019/10/izh-mp532-target-rifle-part-3/)
Could owners of this 46M based rifle, hotrod the velocity? If so, do they? If not, why not...
I hear you buddy regarding the diminishing returns of increasing barrel length, expansion of gas, versus friction imparted by the rifling length but it did happen and achieved 550fps in the 46.
My rule of 25fps per inch was largely based on the cylinder sizes you get with Hw75, P17 etc...but even these vary in regard of the 25fps rule. It was just a generalization.
You are correct that you cannot keep going with barrel length to achieve 12ftlbs doing this. 4ftlbs would be more optimistic but in the case of the 46M there is a bit more available from the cylinder volume. I did not measure the gains per inch with this gun, it could have been 35fps but he did get 550 fps with a variety of pellets.
More usually, modifiers of barrels keep going until the gains are barely a few fps and the modifier deciding the ungainly appearance is not worth it, stopping at an optimum.
This was the case with the P17 mods which are all across the web. I think nothing much happened beyond 10 inches but one character kept going and got 500 fps....so i am inclined to believe the figure for the 46 but im guessing that was about the absolute max.
Go for it. I hope you pull it off..
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This was the dude over on Airgun universe who got 485 fps with a 16 inch barrel....doubling the length of the stock barrel.
It fully suggests the 46m 550fps is a possibility but i conceed i did not personally test it, so no strong argument from me here.
It certainly agrees with what you are saying reg diminishing returns as this could not have been 25fps per inch but still climbing albeit by smaller amounts after the first 2 or 3 inches.
My own findings with the 46M were the aforementioned 400 fps in .22 for stock length and that i had NOT tried the 16inch barrel but well worth the experiment i should think.
I was actually happy with the 440fps i got from my HW75 with decent 8 grain pellets that i prefer.
It was just enough to be able to topple a rat knockdown target i had out to 15 yards which the stock 75 struggled to do. Maybe the odd close range Starlings in the garden but no alteration to its appearance to get here....my main aim.
Other pic is when i was trimming the 9 inch barrel length to get it flush at 8.25 inches finished size.
It was making 448 fps avg at this length.
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Hi All, I didn't have any problem with the seals getting hot in the 12 fpe pumper. The piston uses a buna o-ring seal, and the poppet is a 7 degree angle Delrin toilet plunger, (imagine how thin the edge of the plunger is). I had sent Larry Durham all the dimensions of my gun and he calculated that the final pressure was close to 3000 psi. Some heat must be created, but I think it is probably adsorbed by the large valve body as the air is being compressed. Another indicator of the lack of heat is the absence of moisture in the firing chamber, imo, this is what makes SSP's velocity so consistent, compared to multi pumps in humid climates where the valve s have a sticky mixture of oil and water in them that takes up volume and causes the velocity to vary for a given number of pumps, depending on how much gunk is in the valve. The pump effort on my SSP is about 63-64 lbs. The total weight of the gun is 6.5 lbs. 12.1 fpe. was made with a .22 cal. barrel and 14.3 grain pellet, in .177 the gun made 11.2 fpe. with 10.5 cp's. both barrels were the same length. hth