Ever had a gas key that came loose? I know I have, especially with some of the bargain prices bolt carrier groups that I have bought over the years. The Michiguns MOACKS Plain is designed to allow the home gunsmith the ability to stake the gas key screws properly without expensive machines. This particular BCG is an IWI that I purchased on closeout and hasn’t come loose yet, but it is a matter of time in my opinion.
There are many people that believe that thread locker alone is sufficient but I have had at least two gas keys come loose with only thread locking compound keeping the screws in place. When I attended the Semper Paratus AR-15 armorer’s course we fixed a couple gas keys with the MOACKS Plain, after that I knew I needed to add one to my gun tool box.
You can see the weak staking on the BCG below, we will also replace the screws with the proper grade screws at the same time.
The MOACKS Plain is made from pre-hardened 4130 steel and uses quality screws to accomplish the staking operation. The tool itself is very nicely machined and the included 1/8″, 9/64″, and 5/32″ Allen wrenches are also high-quality US manufactured tools.
The two holes at the top of the tool are so that you are able to index the tool to the proper location. The idea is to stick the long side of the proper Allen key into the hole and make sure it goes into the gas key screw. Your gas key screw could be 1/8″ if the screws are Mil-Spec or 9/64″ if they are the standard commercial grade units.
Two hardened screws on either side of the tool will be tightened in order to stake the gas key properly, the white substance is lube to keep the screws moving smoothly when deforming the gas key.
Removing the commercial grade screws you see that they used thread locker as a backup to the less than ideal staking job. The screws came loose rather easily with just a screwdriver, I didn’t use much torque at all.
In order to make sure the gas key is nice and tight against the bolt carrier body I will need to remove the old thread locker and clean off anything else that might be in the way of the two surfaces mating.
Reinstall the gas key after applying sealant and use new grade 8 screws. They should have a squared head like you see below and fit flush.
Now locate the tool in the proper place with the two holes on top with the proper size Allen wrench and hand tighten the screws on the side.
From this point, it is as simple as tightening the screws till they bottom out on the tool. This will provide a secure and uniform stake on each side of the screws.
You can see the rounded tips of the screws deforming the gas key just enough to provide a secure stake.
The finished product is clearly secure, these screws aren’t going anywhere anytime soon. Just a quick touch up with a bit of cold blue and the job will be done.
Is the Michiguns MOACKS Plain worth the $85 MSRP? Yes, especially if you are a heavy AR shooter like I am. The ability to replace parts like the gas key and bring them back up to snuff or even repair sub-par jobs like was done to this BCG originally is invaluable.