Just to add to the fire, I have a CMC single-stage that got moved to a different, less-used range toy build. It was in my .300BLK SBR, and my original load for subsonics was using IMR4895. Unfortunately, there was a *LOT* of unburned powder and I wasn't really concerning m'self on massively thorough cleanings every range trip. The trigger got unburned powder, CLP, and carbon mixed up inside its inner workings, and as it's a cassette style drop-in, got gummed up pretty good, which first started with the first round of any string (regardless of length) being a 2-3 MOA flyer, eventually resulting in the trigger hammer refusing to drop. I'm using Lil Gun for supers *AND* subs out of that gun now, so no more worries with that, but it also has a G2S-E inside it now which is much better.
It's a good trigger, just rather maintenance-queen-esque, so it's not a good choice for a heavy-use or low-cleaning-regimen rifle.
