TL3 Creedmoor in a KRG W3 Gen5... Magpuls certainly fit without issue, however, they do not work reliably in my setup. Even after considerable trimming and grinding on the feed lips and body the bolt continues to override the round. Working the issue from the other end, I replaced the mag catch with the extended version to dial in feed height but still nada. ARC mags ran without issue even before cutting down the extended mag catch to a perfect height. The improvement I see now is the bolt starts to CRF almost immediately rather than the initial push feed start it had before, if that makes any sense.