Found that one of the gas key's has come loose on it's carrier, apparently the staking that was originally done wasn't done right.  What's the best way to re-stake it?  

I have used a small drill bit in the past w/no problems.  Just about any hard object that will divit the metal should do the trick.

Of course you will want to totally remove the gas key now and thoroughly clean the matching surfaces.

I find a punch and hammer works best.

Not trying to be a smart ass here, but it's just the only way I know to do it.

Mike

What exactly is 'staking' the gas key?

Beetle, I just sold a carrier assembly and have some pictures posted here:

www.jobrelatedstuff.com/forums/topic.html?b=7&f=119&t=221747

You can see where the metal near the key bolts has been dimpled or "staked" to keep the bolts from loosening during operation.

Ah, I see - gracias

Another way:

Go to the INFORMATION tab above and select Manuals & Downloads.

Under DOWNLOADS, select TM 9-1005-319-23 (2.6MB PDF) Unit And Direct Support Maintenance Manual M16A2, M4, M4A1

Go to page 142.  It shows how to restake a new carrier key with a center punch and hammer.  There is probably some special tool or set of pliers that stake the key with the notches on either side of the carrier key screws, but who's likely to have one of those in the field.  A center punch and hammer will do the trick if done per the manual.

Using a bushmaster carrier arn't you.  I had the same problem with mine.  I used a hammer and punch, with a tiny bit of locktight on the screws.  Has worked like a charm for me.