I just got a 6720 literally about three weeks ago. Upper is marked 13629. Bolt carrier is not "C" marked. Bolt says "MPC". All other areas seem to be normal.
Here's one thing I'll say though: inspect it thoroughly.
The first 200 rounds out of the rifle ran fine. Then during cleaning and lubing I noticed the bolt would not go back into the bolt carrier even smacking it with the fatty part of my hand. I pulled the bolt back out and noticed one of the bolt rings was out of the groove and looked like it had been kinked during manufacturing. I replaced all three bolt rings and the rifle ran fine again at the next range session.
I think that bolt ring had been compromised all along and as long as the gun was fully assembled it was held in place. It didn't jump out of the groove until I removed the bolt for cleaning.
A thread on TOS shows a rear detent spring that was badly mangled during final assembly on another Colt model. A 6920 I bought in the middle of 2018 came with a hammer pin that wasn't pushed all the way in to "click" on the retaining spring. Once I pushed it in all the way it was fine.
My point being: It's odd that three problems in a few months have to do with "assembly" issues. I'm thinking Colt or whomever is putting rifles together may have some less than stellar laborers doing the work. I know it's anecdotal but I've owned Colts for years and it's odd for me to have two QC problems in a few months.
Bookmarks