Sir, This is regrettable. The only reason I would replace my G21SF barrel is to shoot lead and I primarily shoot LSWC in .45 ACP. They feed fine in all my stock 1911s and I kind of like the big hole they punch in the target. I'm not good enough as a shooter to actually shoot pistol bullseye but, if I did, I would be shooting 185 gr jacketed SWC. But again, a SWC design... But these bullet choices are just the ones I have made. Others will choose differently. In terms of .45 ACP, I would think that all match shooters would be using 185 gr jacketed SWC. Perhaps that's not true today but it sure used to be. The tighter chamber may help accuracy but to require RN FMJ seems problematic. And, no, I don't have a better answer. I don't even have a dog in this hunt because I have never thought of the Glock as a competitive target pistol. Action pistol? Sure! Bullseye? Not so much... In my view... Richard Wanna kill these ads? We can help!