nitro

The answers above are very useful but should they also include the tensile strength of the copper ?, Thank you very much, however, after all that, will it be safe ? Kind Regards, nitro

Thanks for all your replies. I apologise if I have caused some of you to think that my intentions were less than honourable, but it was a "Physics question" and that is why It was posted in the manner it was. So, as any design IMO must be "Fail safe", given that the rifle in question is a bolt action breech loading (thats one end of the barrel capped off), and should the open end of the silencer become blocked with whatever, (thats the other end capped off)are you saying that 1.1 cubic inches of CO2 at 1000 psi for a period of say 300mS. will not rupture the chamber?. This is not a 28mm i/d void, as a 8mm i/d tube passes through it, with holes of 5mm dia. dilled into it, and then baffles sealed to the inside of the 28mm tube, there a 5 of these, so in essence there will momentarily be 5 separate chambers varying in length from 10mm to 48mm, each receiving an exponential deceleration of pressure. Kind Regards, nitro

In the UK it is fine, I do hold a FAC licence as well. I have found my answer I think using Lame equations. Kind Regards, nitro

Thank you both for your comments. I can assure you that I have no intentions of making a bomb !!!, I am a retired 68 year old Electronic eng. and my Nephew has just purchased one of these new 88 gm. CO2 powered air rifles. He wants a silencer for it, and that I can design, and copper is readily to hand ( domestic heating pipes) in my garage, but I cannot remember or locate the formula for the calculations in lbs/sq.in. for a given pipe size and length - hence the question. I believe the pressure output of such a bottle is in the order of 1000 psi. but should things go wrong, I need to know that the pipe can take that sort of pressure - quite an innocent question really !!. Kind Regards, nitro

Hello, Given a copper tube with capped ends, of 150mm in length, 28mm i/d and a wall thickness of 1.5 mm, can anybody give me the formulae for calculating the pressure that it will withstand prior to rupture at an amb. temp. of +20 deg.C. at ground level? Any answers would be appreciated. Kind Regards, nitro