Greetings from Manchester Mi, I purchased a 24" hvy ss barreled upper in 204. I always lap a new bbl. As I looked down the pipe I saw a burr. I mean .004 of .005 around the gas port. And the hole seemed to be BIG. I mean 1/8 inch or more. So out to the shop I go, patch the bbl out,& begin to lap it. OH OH, big resistance on that spot. I sent it back. They send me the same upper back, w/ a note cleaned out burr w/ a cleaning rod. Nope. same "feel" same .200" gas port mistake. They claim the 204 hole is .006 bigger than the 5.56 hole. None of my 8 ARs have a visually big gas port hole or a definite sticky spot while running a cleaning rod down it. School me on this 204 gas port. Thanks, Red
"It's a long shot with a limb in the way but it beats suckin' pond water"- Jed Clampit 1964