I hit my first snag. In trying to test a full 72 round feed, I found the spring did not have enough pressure to feed without having to slap the drum occasionally. I've found part of the problem, there is a lot of dirt and crap inside the drum, so I need to disassemble and clean it. I also need to re-tension the main spring. No big deal, but something to remember down the road.
With all that said, it fed just fine once I had about 20 rounds out of it, so even without much work, it is already a 50 rounder. Some tuning and tweaking, and I should get all 72 rounds out of it, no problem.
EDIT: I fed WWB FMJ and my cast lead reloads I buy from Wideners.com through it. It eats the reloads all day long, and loads them even better than it does the WWB FMJ ammo.