Algodoo

I converted your slug into a basic detonator grenade. Pretty reliable but not much power. You had better be a good shot to use this.
See my scene response. It should work in your gun (I never tried because I couldn't figure out where to load it ) but it should work because I used your shell.

just make a box with circles fixed to it make springs increase lenth change box collision make small killer box add hinge make hinge moter fix small box to the box witch holds slug together. i cant put the slug in. next next

To load his gun you have to push the pump forward , put the slug in, pull the pump b and then press "G"
Converting your slug now

Converted - My one uses some fancy oncollide in the red oval - and mie is more powerful that 1storange's (including that his one doesn't work in your gun )

oooh... I have no clue how to make a frag or HE 40 mike mike, but I like the M203!