I have a LE6920 lower headed my way that I assume will have the web sear block. I’ve read much conflicting info regarding what BCG will and won’t fit. In searching for a decent upper, I’ve noticed that most manufacturers are shipping their complete uppers with m16 profile BCGs. Will these work with the Colt lowers with the web sear block?

Wait until your lower comes in to confirm but I am pretty sure the 6920 series does use a seat block like the older sporters did. Should work with any ar profile carrier, semi or full auto profile

6920 lowers do not have sear blocks. Any standard profile BCG will work. You will not need a "half moon" BCG or other silliness.

Colt has not installed sear blocks in new-production lowers for the last decade, if not two decades.

quote:

Originally posted by LDD:
6920 lowers do not have sear blocks. Any standard profile BCG will work. You will not need a "half moon" BCG or other silliness.

Colt has not installed sear blocks in new-production lowers for the last decade, if not two decades.

My 2008 production 6920 has the sear block in it.

You sure on this issue. I have 6920's from that time and a bunch of others and the web is not a sear block and any carrier is fine. In fact the factory ones are FA.

My LE marked 6940 has an internal sear block with FA carrier. If it is a pinned sear block, a FA carrier won't work, because they protrude above the receiver, but those are in the older Colt's.

If the lower is blocked, do what I did for my old Colt Sporter Lightweight: Lewis Machine & Tool L7A3 SA BCG

If it's a recent production Colt lower, it won't be blocked, and in that case, I recommend the Colt FA BCG.

Here is a good link showing the difference in Colt lowers.
https://geissele.com/colt-rifle-users-guide/

quote:

Originally posted by swage:

quote:

Originally posted by LDD:
6920 lowers do not have sear blocks. Any standard profile BCG will work. You will not need a "half moon" BCG or other silliness.

Colt has not installed sear blocks in new-production lowers for the last decade, if not two decades.

My 2008 production 6920 has the sear block in it.

That's surprising and disappointing.

None of the 6940s and 6920s that came through my shop had sear blocks.

quote:

Originally posted by swage:

quote:

Originally posted by LDD:
6920 lowers do not have sear blocks. Any standard profile BCG will work. You will not need a "half moon" BCG or other silliness.

Colt has not installed sear blocks in new-production lowers for the last decade, if not two decades.

My 2008 production 6920 has the sear block in it.

Do you mean a web left in the lower where the seat would reside or the actual sear block that was pinned into the lower? I am on my phone or I would link a photo.

https://geissele.com/colt-rifle-users-guide/


Only type 2 causes issues with a BCG.

quote:

Originally posted by Mettlepig:
Here is a good link showing the difference in Colt lowers.
https://geissele.com/colt-rifle-users-guide/

Oops, didn't see this was already posted.

quote:

Originally posted by IndianaBoy:

quote:

Originally posted by swage:

quote:

Originally posted by LDD:
6920 lowers do not have sear blocks. Any standard profile BCG will work. You will not need a "half moon" BCG or other silliness.

Colt has not installed sear blocks in new-production lowers for the last decade, if not two decades.

My 2008 production 6920 has the sear block in it.

Do you mean a web left in the lower where the seat would reside or the actual sear block that was pinned into the lower? I am on my phone or I would link a photo.

It's the web sear block per the OP's description in his post. I realize there were pinned sear blocks in older Colt lowers. Newer production Colt lowers have neither.

quote:

Originally posted by swage:

quote:

Originally posted by IndianaBoy:

quote:

Originally posted by swage:

quote:

Originally posted by LDD:
6920 lowers do not have sear blocks. Any standard profile BCG will work. You will not need a "half moon" BCG or other silliness.

Colt has not installed sear blocks in new-production lowers for the last decade, if not two decades.

My 2008 production 6920 has the sear block in it.

Do you mean a web left in the lower where the seat would reside or the actual sear block that was pinned into the lower? I am on my phone or I would link a photo.

It's the web sear block per the OP's description in his post. I realize there were pinned sear blocks in older Colt lowers. Newer production Colt lowers have neither.

I see the new ones all the time with the block.
Here is a pretty new one that shows it:
http://upstatearmorygroup.com/...pped-lower-receiver/

For clarification: my comments with regard to Colt installing sear blocks were only in regard to the old pinned-in style (as this the pinned in blocks are the only ones that require special carriers).