SpudFiles

Hello, I have been thinking about improving power for my airgun the past months. I spent a lot of money on 2 failed attempts on piston guns. I finaly decided to make a simple, elastic band opened ball valve musket. It could fire 20 gram bolts through 2 1/2 inches of hardened plywood, and embed marbles fully into the blocks. My last shot, I used 20 elastic bands( really good ones), 150 psi to open my valve. It fired a loose fitting marbleand a barrel to chamber ratio of 2/ 1.3 into 13cm of thick carboard at 10 meters, through the other side, chip a concrete wall a scream of into the sky. The speed at which the valve opened was so fast that it broke my trigger mechanism. The marbles wieghed about 4-5 grams and are .63 of an inch. Because of this, it makes a really loud cracking/ whipping noise when shot. If I try really hard I can load aim and fire 1 round every 28 seconds. I have seen a recent video of a ball valve triggered burst disk gun, but lost it and cant find it. Would it work with my stats and how much would it improve the power? I want to know if it can fire my cast, 25 gram .75 minie balls at decent speeds over 400 fps at 250 psi.

dilweed wrote:Would it work with my stats and how much would it improve the power?

Yes, it would work - and I can't tell you, but it would be worth it.

I want to know if it can fire my cast, 25 gram .75 minie balls at decent speeds over 400 fps at 250 psi.

I'd need know how long the barrel was - however, HEAL and it's piston valve are capable of about 600 fps with similar projectile stats when using 300 psi and a 120cm barrel.

My barrel is roughly 90cm long (It kicks like a mule!). I also plan on using a barrel to chamber with a ratio of 1:2.5

Short of making a valveless launcher, a burst disk is basically as good as it gets.

Have a look here, and this is some comparison between a burst disk and similarly sized piston launcher to give you an idea of what a difference in performance it makes.