Algodoo

This is a work in process so i know that the hole thing could be better, the reason i upload at this point is that it malfires and locks up easily and i would like some advice on how to improve it..

sometimes the bullet just bounces off and jams the thing, other times the bullet dont push the slide all the way back.. any ideas on how to make it better?

Just a note: to fire just pull the slide back so it catches a bullet from the mag..