Airgun

[jackssmirkingrevenge]

well i could but im going for an airgun type gun not a cannon and i need it to be cheap and small enough to hide from my parens(they banned all of my others so im going small.)

I won't preach about what you should or shouldn't be doing, I was lucky to have parents too scared to tell me to stop with my experiments, it was fine as long as I confined things to my room. Of course they weren't too happy when a ball bearing ricochet went through my window (see attachments) but I paid for the glass and all was well

You can built the design I linked to with a shorter chamber and smaller (BB?) barrel if you want it to be concealable.

[CpTn_lAw]

that's a fairly clean hole.
Spring pellet gun can be made out with steel, a lathe, and some good welder.
But you need to conceive that if you want to make one, the pressure peak, even short as it might be, is dangerous and causes combusting if any flammable lubricant is used; and for the sake of your gun, you might put some. Plus, your piston needs to be heavy to have some inertia, and therefor not come back when the pressure is to high.
I might think making one...but, it will definatley beat 1000 fps. and i won't use a spring, but a small high-pressure piston-driven compression. like the theoben system.

[jackssmirkingrevenge]

that's a fairly clean hole.

That's the first thing that struck me, the BB must have been going pretty darn fast, otherwise the glass would have shattered. I thought about what would have happened had it come back at my skull instead of my window and needless to say, never tested high-powered projects indoors again

[Redcoat]

im going to make a pneumatic this weekend and i plan to make it like this:

I wil have PVC chamber with a schrader attached(with an air hose)to a blowgun which will then have a 55cm long barrel and the projectile will be rammed down the barrel and after pump up the blowgun trigger is pulled and fires the projectiles.

Also it would be a great help if anyone could tell me if it's worth it and/or how far it will shoot the projecile at 50-60psi.(the projectile is the end of a thumb tac).

Thanks.

[PneuJose]

Of course anything above 50 psi and the thing will blow up

dont 20onz can handle 120 psi? i think they can..

[jackssmirkingrevenge]

dont 20onz can handle 120 psi? i think they can..

If they're made for carbonated drinks, then yes, but I was referring to the improvised fittings...

[CpTn_lAw]

that's a fairly clean hole.

That's the first thing that struck me, the BB must have been going pretty darn fast, otherwise the glass would have shattered. I thought about what would have happened had it come back at my skull instead of my window and needless to say, never tested high-powered projects indoors again

That's a good lesson you leanrt. And i think it is profitable to everybody here to see that. I've seen bullets leave holes less clean.

[jackssmirkingrevenge]

This is the steel plate it ricocheted on, a central hit penetrated but it was the side hit on the left that bounced off.

[PneuJose]

No more indoor shootinng for you

happened to me once, i shot a wall in my back yard with a marble, hit my leg.