- Jul 1, 2009
- Reaction score
Ordered a Polymer 80 PF45 (Glock 20/21) receiver today. For starters, I'm going to build it with a 21 slide and a 20 barrel (10mm). I will eventually get a 21 barrel too (.45 ACP). I would go with the 20 slide, but they are almost impossible to find right now and the 21 slide gives me the option of both calibers. I'll probably use a 20 or 22 lb spring to compensate for the slightly lighter slide when using 10mm. The only real difference is the extractor, but most reports I've read of people dropping a 10mm barrel in the 21 slide say they haven't experienced any problems.