Sealant between carrier and key?

[jaxman7]

This isn't really a pressing question but wanted to know if anyone else has seen this. Buddy brought me another upper to work on......and it came with an R Guns BCG. Yeah yeah.

Anyway this BCG is brand new never fired and I know it has not been tampered with. As per norm for me lately every new carrier I get I sand down the rails with 600 grit sandpaper. Helps smooth the action out a little. While sanding down the left side of the BCG where the carrier & key mate up I noticed it looked like some sort of sealant has been placed between them. In the pic you may be able to see it sandwiched between the two parts. You can definitely see the over run on the rear portion of the key.

Just another observation of lower standard guns. If you need a sealant to keep gas from escaping and can't just rely on the tolerances of each part them that says something.



-Jax

[ZoneOne]

I bought one (ashamed) of the NiB Rguns BCG. I can't take a pic of it at the moment but it didn't have anything like that.

I was actually quite surprised... it looked really good. But I'm not going to put any faith in it. It's simply just a spare.

I love the Rguns policy -- I called, e-mailed, even wrote a letter. I couldn't get any answer when I attempted to cancel my order.

Just about a week ago... it magically appeared in the mail. (I ordered it the first week of Feb)

[Sierra276]

That was originally part of the Mil-Spec requirement...

Not only was the Key supposed to be staked, but permatex was used to ensure a good seal...

[jaxman7]

That was originally part of the Mil-Spec requirement...

Not only was the Key supposed to be staked, but permatex was used to ensure a good seal...

If that's true I wasn't aware of that. Thanks,

-Jax

[Sierra276]

Although it was part of the original requirement, I wasn't aware anyone was still doing it besides Young Manufacturing...

[jaxman7]

So this stuff is permatex?? I scraped the rest off the side of the carrier key and it had a dark red color to it.

-Jax

[Sierra276]

That could be what they have used... I think my Bolt Carriers from Young had small amounts of Red around the Key... but not enough to interfere with function...

I pulled out an Marine Corp Technical Manuel from l984 and this step was omitted... So most manufacturers probably delete it from their process as well..

[polymorpheous]

I thought some manufacturers used Rockset.

[Sierra276]

Are you referring to Rockset applied to the Screws...? I don't know about that, but originally a sealant was used between the Carrier and Key to ensure a positive seal... ( Often Permatex )

Young still uses a sealant, and until now, I was unaware of any other manufactures that still followed this process...

[Dave Berryhill]

I've got copies of the Colt armorer's manuals from the 1990s and I recall it mentioned the use of a Permatex product under the carrier key.