Happy to help :mrgreen:

There are a lot of carriers out there that are very poorly staked..if at all

I saw a post where a PD recently got a dozen Bushmasters and none were properly staked...one was actually loose

Other than bad ammo carrier keys and bolt breakage are two of the biggest reasons for an AR to go down hard

This guy sells a really good staking tool...a little pricey

http://www.m-guns.com/tools.php

he just came out with a simpler one that goes for $70