While you can "fit" a 14mm poppet inside a Disco tube, I have no idea how you could allow enough flow past it, and retain enough wall thickness for the structural integrity of the valve itself....Bob
I am not hoping to do that. I think that would be the result of poor planning however its fun to try to figure out how to make something "work". Actually, I wasn't even planning on using my spare disco tube for a big bore (this season) as I dont have a whole lot of time for extra projects. I was just trying to figure out the calculation for volume for "deer gun". I have another project almost done trying to figure out if it should be 44 or 35. I think the "Outlaw" pistols are a good indication of power for volume too.Now, I think this is great information for someone who wants to make a bigbore breech for the disco. A little more work though getting all the parts modified but doable. But of course is the FPE enough for whatever you are going to use it for?? Choose your forum post of arguments, caveats and warnings. I am hoping for more than 150 FPE though. I was plagued by bad equipment, hunting as a youth before I knew better. So I don't want to chase "pie plates" at 50 yds anymore!
If you go up on caliber, remember that the load pushing back on the bolt goes up with the square of the caliber, so a .357 has 4 times the force of a .177 cal.... and a .44 cal 4 times that of a .22 cal.... Make sure you beef up the bolt handle or other locking mechanism.... If you aren't building a balanced valve you are in for a shock just how much hammer strike it takes to open a 1/2" poppet at 3000 psi.... Bob
On my .308 I use 3000 PSI and have 1/4" TP to the bolt face (so less force due to area).
QuoteOn my .308 I use 3000 PSI and have 1/4" TP to the bolt face (so less force due to area).Sorry, but if the bolt allows you to load a .308 cal bullet, then it must pass through a hole at least that large, so the sealing area is at least 0.0745 sq.in.... At 3000 psi, that is 223 lbf. and the minimum shear strength you should use would be at least 3X that, so able to take a shear load of 670 lbf. minimum....On a .429 cal, the bolt lockup should be designed to withstand at least 1300 lbf. of shear....Bob
20200923_210549 by murphyrobert9, on Flickrthaats basically it , if the gun is empty , the pins could almost be pushed out by hand.. the air pressure really keeps them in place.