Step 1: Acquire a 100v stick welder, a cheap dremel, and a couple pieces of pipe from the hardware store. 1/2 and 3/4-inch OD, preferably.
Step 2: Butcher the everloving shit out of it with popcorn welds and tiny cutoff discs on your garage floor until it drops haphazardly into your $2400 custom 1911 frame.
Step 3: Endure endless failures to feed and cycle, bulged or separated case heads, shorn jackets and cores, and possibly missing fingers and eyes from the hand grenade you just built.