I think it's over gassed.

Ran 60 rounds through my AR build, the brass had little dents in it and was being thrown to roughly the 2-2:30 position rather than the 3-4 position.

Barrel is a 16" medium contour from Sionics Weapon Systems, I'm running an H2 buffer and was shooting XM193.

I haven't noticed dented brass in the past with this build, could it have been a hotter lot of ammunition? Or should I contact Sionics?

Barrel is a mid-length, and while at the moment I can't provide pictures, here is one off google that describes the extreme end of the dents I have.

http://bootifullproductions.com/IMG_3996.JPG


I'll also say that I measured the gas port in a jerry-rigged kinda way. I don't have a pin-gauge set so I basically stuck a pencil in the gas port and started to rotate, the graphite eventually took the shape of the gas port. Took out the calipers (Pittsburgh but it'll do) and measured the pencil lead and came out to be .075-.076. Which seems to be consistent with other brands.