I just received my 16" med-con upper and assembled my carbine. Everything went together as-expected. I wanted to take a look at the barrel so I took the handguards off - that's when I realized there is not the first marking on the barrel - not 5.56, not 1/7, not nothing. I was somewhat disappointed in this and its not really a big deal, but even Olympic puts the caliber on the barrel.
SORRY, CMMG. THE BARREL IS CORRECTLY MARKED