9.3mm Hunting Air-rifle

[MisterDoctor]

I was randomly inspired to construct an airgun last week. Since then, I've done tons of research on the topic. I've learned how to construct a QEV, and how to assemble a basic airgun powerful enough to send a double-A battery through half inch particle board. So, what I'm here to pick your brains about is this new idea I've had. I want to make an airgun that fires actual rifle rounds. No powder, just the bullet. I have the stainless steel barrel, the ID is .37" and OD is .50". I basically need suggestions as to what else I need to fill in the blanks. I would like it to be semi-automatic, if possible. So guys, what do you say? Possible?

By the way, here's my inspiration: [youtube][/youtube]

[Gun Freak]

Semi auto with a gun that doesn't fire spherical ammo is difficult. Blowback would be cool but difficult to implement. What would be more practical is a breech load that can be easily operated. Bolt action esque, maybe.
You're gonna want high pressure. A QEV with a slide valve will give you semi auto firing. For an air source a CO2 tank with reg or an HPA tank with a reg would be sufficient.

[POLAND_SPUD]

what you want is this >
http://www.spudfiles.com/forums/files/s ... ii_400.gif

you need a 3 way valve and an air cylinder to build it (I assume you already have a QEV)

EDIT
a slide check valve is a 3 way valve...
ohh and you need a T that can accept nonspherical ammo, but that's not a problem you just need a rectangular slot there rather a drilled hole like in the animation

EDIT #2
I hope you know it won't be very accurate because your barrel is not rifled ? the projectile will tumble in flight

[MisterDoctor]

You mean breach load? I had a feeling this was going to be a fantasy. But bolt action actually seems more attractive to me anyways. So, I need a tank with a regulator? What would I be looking for, specifically? Here's the round:
http://www.amazon.com/Nosler-46029-9-3m ... B000PWA8VY

[Gun Freak]

Oops I meant breech load not breed, edited accordingly.
Breech load=bolt action.
Give me a sec, quick diagram coming up.

[MisterDoctor]

Forsooth. Hey Pole, thanks for the animation. It gives me hope, ha ha.

[Gun Freak]

Read Poland's edits.

[MisterDoctor]

I'm working on a rifling machine now. Found blues from a different website I'm using. But I understand what you're showing me. The problem is, I can't find any tees small and capable of supporting 200+psi. That goes with most of the fittings I'd be purchasing. I've been on Home Depot all night making lists and junk, only to find the fittings I was going to buy were 150psi test. Problem?

[Gun Freak]

Brass? Home depot has all the fittings in that drawing. The bolt and modifications to the barrel tee would be up to you.

[MisterDoctor]

I'll continue in the morning. I'll get back to you with a diagram and a video or so describing the parts I'm using. Thanks, guys.

[warhead052]

Those "150 psi" ratings are capable of 1,000 psi. Its a huge safety margin.

[Zeus]

Remember, unless the projectiles can conform to the rifling, then rifling is pretty much pointless. I doubt you'd be using pressures high enough to pass the bullet through a forcing cone into the rifling, then you'd better have the tail of the projectile hollow so it can expand into the rifling, like an air rifle pellet.

Just because the fittings state the rating as 150PSI, doesn't mean that's the yield pressure. Brass has been used at unregged CO₂ pressures, so I wouldn't be concerned with 200PSI.

[MrCrowley]

I'm with Zeus on this one, not even a 10x hybrid would be capable of rifling a real rifle round in a real barrel. I don't even know how well it could be done with lead rounds.

If your custom made barrel happened to impart some what of a spin on the projectile, I doubt it would be enough to stabilise it in flight. I'd stick to shooting smooth bore projectiles that have fins or tails or whatever to stabilise them.

[mobile chernobyl]

I like the welded stainless pressure chamber!

[Crna Legija]

I like the welded stainless pressure chamber!

thats a french guys gun it been posted hear somewhere.

im surprised no one's mentioned that hunting talk with home made guns is not allowed hear.