The MOACKS II supersedes and replaces the original MOACKS. It is lighter and smaller, taking up less space in your toolbox, and offers the additional feature of being capable of counter-staking the screw. Also, positive alignement can now be had by using one of the included Allen wrenches to locate the tool to the bolt carrier. Note: Always wear safety glasses when working on your rifle. It is not unknown for Allen wrenches to break and send shards flying. I am not responsible for anything related to this or any of my products, or their use or misuse, other than to make sure they are well-built tools that you will find useful in working on AR15's.
This goof-proof tool makes it easy to get some real manly stakes on the carrier key, preventing the screws from coming loose. This is one of the most common malfunction-causing problems suffered by these rifles. With this tool there is little or no technique required and little or no chance of messing it up, as there is when trying to do it with a hammer and punch. Just tighten the tool's staking screws until they bottom out and you're ready to go; the formed and hardened screw tips diplace carrier key metal over the carrier key screws. One of my good friends has dubbed this tool "The Mother Of All Carrier Key Stakers".
The block also features a bolt tail scraper. The back end of the bolt can get caked with carbon where it is directly exposed to gas tapped from the barrel. It's bad form to clean this with a wire brush as you might damage or even inadvertently remove a gas ring. This tool makes it easy to do a good job on this hard to clean area and is pretty much impossible to use wrong. Just stick the bolt tail in, push and twist.
MOACKS II comes with three Allen wrenches, 1/8" and 9/64" (carrier key screw socket sizes vary), and a 5/32" for turning in the staking screws. The tool is made from heat-treated 4140 steel, and comes with a carrier bore scraper and a gas tube clamp. The carrier scraper tool is used for scraping carbon deposits from the bottom of the bore in the carrier where the bolt rides. This area is directly exposed to barrel gas and can tend to get quite a build up of residue. To be honest, I have not heard of problems stemming from failing to clean this area, or from failing to clean buildup on the bolt tail. But my concern has always been that allowing a buildup in these two areas would reduce the volume available for tapped barrel gas to expand into, and this is exactly what makes these rifles cycle. Secondly, I'm concerned that large deposits may eventually decide to fall off in big chunks. This would be something akin to having a chunk of carbon the size of an Oreo bouncing around in your car engine's combustion chamber.
The MOACKS carrier scraper head holds the scraper handle in place for storage. The scraper head also acts as the clamp screw for the gas tube clamp, which is the second function of the scraper handle. The gas tube clamp allows you to wiggle and pull a reluctant, crudded-in gas tube. It also aids in aligning and pushing it in upon reinstallation.