Submitted by Eric Daniel
For those of you who have never fired it, the M-240 series machine guns are solid performers. Reliable, and possessing a high ROF, they are a great weapon to have in your bag. The only downside I've ever had with it though is the difficulty in cleaning the carbon buildup off of the gas piston cup. Powder residue is constantly deposited in that cup and on the operating rod behind it, and after a couple of thousand rounds, stripping all that fouling off can be a real chore.
While the Army does field a couple of tools that will help remove some of that buildup, traditionally, it has required a lot of elbow grease and a couple of blunt instruments.
Well, being the avid hobbyist that I am, I have a number of Dremel tools at the house, and one day I decided to bring my battery powered portable to Graf with me to see how it would work on that carbon. Long story short, it was brilliant. With a bristle wire wheel attached, the Dremel strips off the buildup but leaves the cup and rod undamaged (the steel in the operating rod is harder than the wire in the brush.)
My Dremel, purchased in the 80's, ran off of four AA batteries, which would provide power for about an half an hour of continuous use. Dremel now makes their 4.8v cordless with a built in, rechargeable battery pack, which is replaceable, so you can purchase multiple packs.
If you're looking for a "garrison" model, with a dedicated power source, I'd recommend any of their stock models (I have the multi-speed) with the flex shaft extension, so all you have to hold on to is the tool tip.