have the tools, and know how. A certain guy once made and mounted 40 .22 cans on 40 Jennings pistols, in 4 days. That time frame INCLUDED hanging them, priming them, and painting them wrought iron black, testfiring, and stamping a number on each, to match a number he also stamped on the pistol. They got traded for pot, in Belize, but were supposed to get traded for many x as much $-amount in Coke,actually. "mass-production' methods, of course, speed up any maching-assembly job. All the set up time, for each maching and job, is where you lose all your time. Once set up, running 40 pcs usually takes a lot less time than did the orignal tool setup.