specifically: https://www.thingiverse.com/thing:2573171 Is the creator here? anyone print this out with success? It uses an M100 aeg spring to fling bb's on impact. If people are interested, im also planning to design a 3D printed BFG. again, an aeg spring looks like a great powersource for a firing pin. similar to this: looks as if the trigger are the side pieces/pegs come off on impact releasing the firing pin. Now what is a good cartridge? shotgun primers are widely used already. I see blank .22 in home improvement stores for ramsets with varying power levels. i feel like that can give a great volume adjustability. thoughts?