Searching for a rare part

[MitchWerbellsGhost87]

Anybody have one of these old oval hole barrel extensions for the M11 .380 (5/8x11 TPI) ?

These had to have been made by CMP out of Atlanta at some point in the early 80s, I have seen OEM RPB 18” M10 and M11 carbine uppers with the same heat shield, I have one as a matter of fact, with the same exact oval holes with beveled edges… I believe all of those stamped components were done by CMP for RPB, so I believe these barrel extensions were also made by CMP and probably sold by RPB for a short time.

If anyone has one in .380 it would be awesome as I am searching for one for my collection for quite some time now but I can only ever find the 9mm example. I know for a fact they did .380 and .45 like this as well, but they are proving to be pretty elusive.

For some reason all the tools at the top of my box here are grayed out so I can only Post the photo as an attachment at the moment.

And no these are NOT the new extensions sold by FTF or US machine gun and I’m not interested in those. Thanks.

 

[theduke]

Never knew this was a thing.
I guess they are kinda oval....you gotta look close.

 

[MitchWerbellsGhost87]

Never knew this was a thing.
I guess they are kinda oval....you gotta look close.

I doubt anyone has ever noticed it’s a thing besides me lol. They’re not quite oval, but not perfectly round either.

Here’s the same exact holes on an RPB 18” M10/45 carbine top. The holes themselves are round but they have an oblong beveled edge

For some reason I still don’t have the option to imbed a photo, the whole toolbar is grayed out.

Photo attached

 

[JackBlundell]

I have one of those in 9mm. Sure enough, the holes are not quite round. I've had it for decades, and never noticed!

I learn something practically every time I read this forum,

 

[Gaujo]

I've got one somewhere in .45