Carrier key staking question

[Todd Smith]

Hello all, have any of you ever installed a carrier key successfully? I was using Loc-tite (red) to hold the screws in my carrier, and it worked fine. Like a fool, I decided to "stake" the screws in place, which I was lead to believe was the only way to properly install this part. When I tried to stake the key, from the sides like the military does, the damn key split before the metal was crimped far enough to touch the screw & hold it in place. Am I doing something wrong? Now I am tempted to go back to Loc-tite, at least it worked. Maybe the key wasn't heat treated properly(?) Any suggestions would be greatly appreciated. Thanks, Todd.

[Krupski]

Hello all, have any of you ever installed a carrier key successfully? I was using Loc-tite (red) to hold the screws in my carrier, and it worked fine. Like a fool, I decided to "stake" the screws in place, which I was lead to believe was the only way to properly install this part. When I tried to stake the key, from the sides like the military does, the damn key split before the metal was crimped far enough to touch the screw & hold it in place.

The military TM's say to stake each screw in THREE places (which I don't think is necessary).

Don't stake on the sides... because that's where the metal is the thinnest. Stake in-line with the bolt carrier, or diagonally so that there is more metal.

And, you should stake the carrier key into the screw heads, NOT the screw heads into the carrier key. The socket head cap screws are VERY hard and you'll never get a good stake into a screw head.

I wouldn't trust Loctite because it gets soft and weak when it warms up.

Loctite red will break an Allen wrench before it lets go... but warm it up some and the screw will come right out.

BTW, what are you using to do the staking? A round pointed punch (hopefully).

Roger

[Todd Smith]

I was using a hardened steel punch. I tried to stake it from the sides, like the Colt factory M16 carriers I have seen in the past. This didn't work. Thanks for the info on where I should stake. I think that 2 good stakes inline with the carrier should hold "em, 2 per screw. The Loctite was a temporary measure, I know that heat will soften the stuff right up. I'll let you all know if this method works, (the staking that is.) The anxiety is part of the fun of doing your own gunsmithing! Todd.

[Circuits]

I usually use a center punch for staking carrier key screws - sharp, hardened/ground tip, and easy repeats to get the staking effect you want.

[Todd Smith]

I how have about 400 rounds thru the rifle with the key staked in this manner with no problems. I would reccomend that others wishing to "do it themselves" stake the key once in front of the screw and once behind as you look at the carrier lengthwise. Be sure to stake relatively close to the hole so the metal "flows" against the screw, holding it solidly in place. I used a sharp center punch too. Thanks again everyone for your responses to my thread. Todd. :sniper:

[scalawag]

i work on mechanical things alot, guns are just one of them. and i have yet to see any factory do this.

take the screws out file a small notch in them on outside edge, torque correctly, then push, ie stake the metal into the filed notch. there will be no way it will ever move. i took my screws out did that, now i know it wont move.

[Epinephrine]

Takes too long for a factory to do since the regular staking works. Time is money as they say. Now, I have never staked my carrier, but if I ever need to, do you need a torque wrench or do you just screw em down until you cant tighten em any more with the long arm of an allen key?

[Circuits]

There is a torque spec, although nice and snug with an allen wrench should work, too. Torque specs are available in the M16 field manual, which you can download free in .pdf format from many sources on the web.