Unfortunately, it's extremely difficult to control the velocities of the BB's with a powder driven device like this. Some BB's may just pop out at around 100 to 400 fps, while most will probably zing out around 600 to 800 or more (fps). Of course, this is largely dependent on the size of the actuating charge and the strength of the frangible shell (body). Needless to say, those velocities could put a serious hurt on you or your opponant. I sympathize with you though. A good grenade can really add some excitement to the party.
TheRev
Is there any hole in me that's bleeding more than the others?