M14 style pneumatic replica

[sputnick]

For a while now, I have been considering making a pneumatic replica of an M14, also to be my first go at piston actuation.

The body is likely going to be 1 1/2 inch PVC, the barrel: 1/2 inch copper

The vertical section of the pipe would be like the magazine of the m14, and it would be triggered by a blowgun (unless any better ideas are given, sprinkler valves are out of the question)

Just figured I would put it here for anyone who wants it, and to see if anyone could offer any possible design improvements!

The internal drawing was done on auto cad, then transferred to paint, so it is to scale.

The stock would be made in 3 parts, so that I could just cut pieces out of the middle section for the pipe, rather than have to chisel or drill out from one solid piece.

I know it is nothing really special, but I wanted to see what people think before diving in. I also would not be able to build it very soon, because I would need to go looking for the PVC, and I (like a fool) have been using non pressure rated ABS for my entire spud gun career, and am lucky to still have my hands.

Should I build it?

[pocket]

should work ive considered this design with an L96 type of tosser my only flaw was pointing the piloted air away from me.

possible pilot valve could be a safety release valve?

[sputnick]

Well with mine, there would be either galvanised pipes or hose going down to the grip, where the blowgun trigger would be. so the vent is going down through my hand

This design would also work easily into the design of the L96A1, all you would need is a different stock, some dovetail rails and perhaps a shorter "magasine" tube.

[pocket]

yes my design worked out to a spring loaded ball valve foolishly after finishing i realized the pilot exhaust was going right into my right eye so unfortunately it was never used often

[sputnick]

Do you have any pictures of the gun? This will be my first piston gun, so I would like to see a similar working model...

[pocket]

unfortunately no i don't i claimed it a fail when i realized i completely fucked it up. the parts were un-soldered and thrown in the parts bin sorry.

[raptorforce]

yes it will be awesome when you make it i was thinking about making on to but i want to see how your turns out first

[jackssmirkingrevenge]

Looks good, I would suggest making sure the construction could take at least 300 psi so you could pressurise it with a shock pump and exploit the power potential to the full.

[hi]

i suggest buying a stock set for an m1a or m14 on ebay or something like that. making a stock your self would be difficult i think, unless you have done it before.

[daccel]

I can attest to stock making being difficult, but it is satisfying when it's done. Think about how the grain runs through the hand grip part by the trigger because if the butt is too much below the front that can be a weak point. Mine cracked there when I lightly dropped it.

Are you going to cover the chamber to look more like the real magazine? If the pipe is too wide you could reduce to a smaller size and tee to two vertical chambers. Or even make it a coax/t combo and extend the chamber forward a ways along the barrel.

A thought for improving aesthetics with the pilot - put a 90 elbow, then a 45, then the blowgun. This way you could have the entire blowgun inside the stock with just the trigger sticking out. Though the extra pilot volume would reduce performance. There's (almost) always a trade off.

And I second Jack's call for high pressure materials. Realistic firearm replicas force you to use fairly small parts, which makes the pressure important.

[raptorforce]

when i was thinking of my design my air chamber went into the stock which would make a bigger chamber but it might be weaker because there is less wood or might be stronger because the pipe is like a steel rebarb in reinforced cement im not sure