Bringing this thread back up as I've just started shooting 2 cases of 6CM 115g Prime that I purchased. First off average velocity has been right about 2,905fps out of a 26" 7.5T Proof steel barrel - not even 60 rounds down the tube yet though so hopefully I pick up some nice velocity gains. Gun and ammo are shooting .4-.6MOA five shot groups. It's a new gun and all I've put through it so far has been the 115g Prime, so not sure what gun is capable of with anything else, but 1/2moa is acceptable to me with factory ammo.
What's been a little troubling is velocity spread. My first trip out when chrono'ing I had one shot at 2,745fps which put the 5 shot string at an ES of 176! Subsequent trips and I've seen ES spreads of 50-60fps. I know this factory ammo, but at least in my head I'd put Prime a notch above something like Hornady factory ammo, but given the velocity spreads and accuracy it's about on par.