CR6920

**the AR-15 Junkie** · 05-09-21, 21:21

Originally Posted by VIP3R 237

Exactly. I’d love to see Chad from SOTAR go through a CR6920 with his knowledge and tools and give us his thoughts.

Ive bought a cr6920 and a cr6960 and I haven’t seen a quality drop from my le6920.

LMAO!

**Rogue556** · 05-09-21, 21:25

Well, I decided to make use of a Colt lower I've had laying around. I ordered a Colt 11.5" 6933 upper receiver and Colt BCG from Brownells last week which arrived via FedEx today. The BCG was not purchased as a complete upper package with the upper receiver, but purchased as a separate item on the same invoice. (Pics Below)

Upper is square forge and marked with Colt's cage code.

Barrel is marked with Colt's cage code and still sports the "MP" marking.

The barrel toward the chamber is marked with an "R". After some research, it appears this is the marking of the company Colt sourced the barrel from. I've heard some say they believe the "R" to be Rock Creek, but after some digging I think it's more likely Rosco Mfg. (If someone actually knows for sure, feel free to correct me).

The handguards do not appear to have epoxy.

The upper receiver itself appears to be fine. I did, however, have an issue with the BCG that I received. The BCG would not seat into battery correctly without an excessive amount of force. Removing the BCG was nearly impossible. The BCG required an extreme amount of force be applied to the charging handle to force the BCG rearward and out of battery.. So much force, in fact, that I managed to break the roll pin on my charging handle in the process (Old used BCM charging handle I had in the parts bin, not a new Colt).

Here are some pictures for the BCG in question. (Colt BCG part # SP64028).

(Edited to add): Here is a picture of the bolt markings. The bolt is very faintly marked "MPC" and also has an "A" as well. I'm not sure exactly what the "A" is referencing. Date code or manufacturer maybe?

I believe the BCG was getting hung up on the front corner of the gas key where the key contacts the carrier. In the picture below you can see peening and anodizing removed from that area of the gas key. There are also other areas of the BCG where the anodizing was removed from contact that do not come through in pictures. Another area of excessive contact appears to be the bottom "rails" of the BCG that slide against the receiver. That area appears to be ever so slightly out of spec, causing the BCG "rails" to make
too much contact with the receiver as the BCG comes forward into battery, thus locking the gun up with the bolt all the way forward.

I verified the upper receiver was not at fault by using two other BCGs (BCM and Colt) and inserting them into the new Colt 6933 upper. Those BCGs had no issues in the new upper receiver. The new trouble BCG in question was inserted into a known reliable upper receiver (older Colt 6920) and it too had issues with the trouble BCG getting stuck in the forward position (though not as bad as it was in the new Colt 6933 upper receiver).

I will be contacting Brownells in the morning for an RMA and getting this one swapped out or receiving a refund.

This is a sample size of one, but I feel it is relevant.

As mentioned in a previous thread, I've had more issues with parts from known quality manufacturers in the past two years than in the previous 10 years combined. I'm not surprised by it at this point, and I halfway expected it. If you guys are buying gun related parts in any high amount and you are NOT having these issues, do yourself a favor and buy a lottery ticket. This may or may not be an indication of Colt QC slipping due to outsourcing of parts, but it is a data point. Take it for what it's worth.

**georgeib** · 05-10-21, 07:22

^ It looks like the the front lower edge of the gas key is wider than the top.

**Stickman** · 05-10-21, 07:51

Rogue,

Thank you very much for updating this thread with first hand info, it goes a long way.

**Rogue556** · 05-10-21, 13:00

Originally Posted by georgeib

^ It looks like the the front lower edge of the gas key is wider than the top.

That was my impression of it as well. I don't have a micrometer on hand to verify, but it does appear to protrude farther on that one section of the gas key than it should.

Originally Posted by Stickman

Rogue,

Thank you very much for updating this thread with first hand info, it goes a long way.

No problem at all. I spoke to Brownells customer service earlier this morning and they were more than willing to help. After a detailed explanation of the issue they sent an RMA via email and they are shipping out a replacement BCG today. Hopefully the replacement is free of any issues, we shall see.

**Arch** · 05-10-21, 22:36

Rogue556,
I had a Colt BCG (C marked carrier and MPC marked bolt) purchased new from Shark Arms that wouldn’t seat in any of the Colt factory uppers I had at the time.

After swapping the bolt out of the carrier I found it would seat. 100% the bolt. Never figured out why it wouldn’t seat. Sold it to a Colt “collector” with full disclosure (doesn’t fit) for $25 shipped.

**Arch** · 05-10-21, 22:47

I picked up a CR6920 last week:

Cage Code MP marked barrel with “R” near chamber.

Code Code upper with M4 on front.

C marked carrier.

MPC bolt with “A”.

No glue on the HGs.

Both P&S and Colt’s cage code on the stock.

No “F” marked FSB.

“F1” marked pistol grip.

The weird part ... the hammer is “F1” marked ...

I bought my first Colt AR in 1984, and have owned more of them during the past 37 years than I care to mention.

The CR6920 has a few cosmetic differences from the LE6920s I owned in the past (I bought my first the day after the AWB sunset and had a bunch over the years).

Looks can be deceiving. If the QA / QC isn’t there then you truly are “buying a name”. However, apart from markings there hasn’t been any definitive proof that the CR is different than the LE.

Regarding outsourcing and markings ... all of the 6520s I owned had G marked barrels.

ETA: in the FWIW department... the CR6920 I just picked up is the only Colt I own now. I just wanted one to use as a beater / trainer / class gun that I didn’t care about .