This is a parametric ECM rifling mandrel in FreeCAD form, with a readme on how to set up your own mandrel for your own caliber and length of barrel. This is intended for use with any ECM type rifling process as done in the making of the FGC, so that it can open the door to people making guns in calibers besides 9x19- although, since that's the most popular caliber out there, an STL of a mandrel in it is included in the release as an example.

WARNING: this is an ECM rifling mandrel with infinite adjustability but NOT infinite usability! don't try to make an artillery barrel with this- those need "progressive rifling" so that they slowly accelerate the projectile up to the full spin, and don't tear it apart with the sudden angle change as it hits and engages rifling grooves. The limiting factor is the circumference and the velocity, vs the materials you can make bore and bullet out of. This Mandrel is made for pistols, it MAY be of some limited utility for medium caliber rifle rounds, it is probably not suitable for anything cooler than that.

LBRY Tags: 3d printing; firearms