Swaging has intrigued me for a while; so yesterday I made a simple die to squeeze some home cast .400" round balls I had laying around from a lead deal into little wadcutters for my 9.4 Dutch revolver. Light .379" bullets are not exactly common. Basically, the die is a cut down Pacific .220 Swift seater die (I have a bucket full of junk dies) with the threaded portion reamed to .379", the neck portion of the die left intact to guide the punch, and the punch turned to fit the neck and reamed portions closely with the end cut for the nose profile. It also worked well turning a little 115 gr .38 wadcutter into shorter, fatter .379" wadcutters. I just use my HF arbor press to mash these little cylinders, but need to turn a depth stop or two for consistent results. I left them with a tiny bit of a bevel base from starting out round for easier loading.