1/2
The only difference I can note is some machining tool marks on the gas key and obviously the BCG is marked Geissele and the bolt has a G.
What is the Difference between the Geissele contract BCG (top), Geissele marked BCG (bottom), and REBCG (not pictured)?
Other user already discussed the contract bcg
The other too 2 are the same. They just stopped putting “REBCG” on it.
Something else of note, the super duty’s come with a REBCG that has a unique cam pin that will only work in a Geissele upper. The REBCG that ships in the URGI and the one they sell separately does not have the unique pin and can work in any upper.
Thanks that’s super interesting. I just googled the cam pin you mentioned and noticed the flare. I didn’t realize the Super Duty upper receivers were different either.
I had never given this any thought as I’ve had the contract BCG for some time and bought a spare BCG off GAFS to throw on the shelf.
The cam pin on the super duty is so nice. I run it on mine and is butter smooth.
Interesting, I didn't know they weren't compatible. I'll have to check when I get home (work firewall) and see if the site mentions they're incompatible with other uppers.
The ones on the site aren’t the ones in the super duty. Idk if the super duty will mention it. But check your giessele receivers. You’ll see a little extra notch inside where the pin sits.
That’s good to know. Can you use any BCG in the super duty upper or will it only take the REBCG?
Any.
The Geissele contract BCG for the URGI does not have the nanoweapon (Chrome nitride) coating. The contract BCGs for the military weren't even made by Geissele. Geissele did the design work, but another defense contractor actually manufactured them.
The marked BCG goes to 11
The bottom one is an rebcg by the looks of it. Has the surgical steel cam pin and extractor and the carrier is marked geissele.
Top BCG is contracted out to white label manufacturers. You can tell by details on the ga key like staking and the bolt.
Bottom bcg is a REBCG without the unique cam pin that comes in the BCGs in super duty’s.
The name for starters.
REBCG has a different coating that’s slick and, most importantly, a forged bolt using what they state is a better material than C158. To date, I’m not aware of a single broken $G RE bolt.