have hi cap glock mags for both; been led to understand that the 40 is pretty potent over the 9mm out of a carbine. stern defense makes ar15 conversion units for both [ MAG-AD9 W/ MOD4 15'' M-LOK 16.1''BARREL 40SW RIFLE UPPER KIT ] do you know anything about the companies product quality or should i wait for the sold out not to be found anywhere ruger pcc. facts only please; no 40 cal hater rants