I don't own a Glock that doesn't have a KKM bbl for it. Great chambers, drop in fit, accurate, IMO stronger (but that's subjective). They even seem to clean up more easily from fouling. When I got my G20 Gen3, I shot some UW 180g XTP's that cases bulged to the point I wouldn't reload them. I bought a KKM 4.6" and shot the same loads out of the same box and no bulges. They reloaded fine, as well. So that was good enough for me and why i always recommend them... esp when you shoot lead or hot/max loads. Congrats on your G20 Gen4, BTW!