So I didn't realize it until I actually bought one, but the 33round Glock mags are actually 31 round mags with a +2 extension. The 33 rounder for me is mostly for kicks and giggles, and I doubt I would ever use it in an SD role, but adding 2 rounds to my G19 actually would be useful. Can I just swap out the baseplates? Effectively making my G18 mag a 31 rounder and one of my G19 mags a 17 rounder? Or is there something different about them? Or different springs needed or something?