I have a gen 4 G21. Other than an aftermarket barrel (.45 to 10mm) and 10mm mags what else do I need to convert to 10mm? Do I need to change recoile springs & extractor? Any help would be appreciated.
You can do it with an RSA and extractor change. But I wouldn't use it for defense.
The best way to do this change for maximum reliability is to swap out for a complete G20 upper, which will fit right onto your G21 frame.
You can get the uppers from Glockmeister.
I have had good results with just using a 10 mm barrel. Used stock RSA and no FTE or FTF. I only fired a little over 200 rds. Like 4949 said, I would not use it for sd.
Thank you for the help.