Originally Posted By altopwescap:
If the receiver were a CMMG it should have an "M" above the cloverleaf port where the gas tube enters the receiver and an "L" on the rear take down lug (LAR). That is based on my CMMG upper. If the barrel is a CMMG it will have a silver colored crush washer behind the muzzle break. The barrel would also be stamped on the underside of the barrel under the handguard. My FSC (front sight) is "F" marked on one side with a "B" in an elongated hex box followed by the number 1.
Is there rough machine marks on the inside of the receiver?
Does anyone else have an upper like this? I have one and the machining on the inside of the receiver left a rough finish. It doesn't seem to affect the function, but it is very annoying. When i operate the bolt it sounds like there's someone in Corduroy pants walking by. I bought the complete upper from Feararmory.com who advertised it as a CMMG upper. The barrel is marked CMMG, but i don't know how to tell if it's CMMG's upper. I'm about to buy a different upper and rebuild it.