i am new to this forum but i must say i read a lot of interesting ideas. I am designing a helium powered cannon for small particles. These particles are so called fsp's and rcc's
right circular cylinders (RCC) and fragment-simulating projectiles (FSP) are used. RCCs and FSPs are non-deformable (hard steel) projectiles normally ranging in weight from 2 grains to 64 grains. They simulate fragment impacts from hand grenades and land mines.
Now have i got the basics working. It can shoot etc, but it needs a redesign since it is not practical. The first tests where to see if we could reach the needed speeds accurately enough. And it does do speeds of 600m/s using helium and the right barrel. Sorry i am in a metric country

So i was wondering if there is anybody overhere that knows any.
Regards,
Per