[mineralman55]

I clean my rifles after each use, barrel/bolt/chamber etc., but I never cleaned the gas cylinder. Sooo, embarassed as I am, after 20+ years I finally took my gas cylinder apart for cleaning. The rifle has always functioned perfectly, it still gets <2MOA regardless of the loads, but the cylinder was grundgy. I used alcohol only to clean it, and various plastic bore brushes, mops and brass brushes to get into everything. I could only get a "K" sized drill bit into the cylinder to clean it out. From what I read here it should take an "O" size? A lot of black came off of the various parts, but I gave it a final rub down with alcohol, let it dry and reassembled it. Gas plug gets 10-15 ft-lbs of torque, right?

I'm wondering, is there a better cleaner for this purpose than alcohol? I like using it because it's cheap, obviously dries quickly and leaves a grease-free environment in the cylinder. Also wondering what are the official/proper bit sizes needed for complete gas cylinder cleaning?

 

[mineralman55]

Bit Sizes

"O" size drill is for cleaning out the gas plug, "P" and #15 size drills for the piston.

#15 bit was waaay too big for the small hole in the cylinder. There is no carbon in the hole and a #27 fit just fine. I got a $3 can of brake cleaner and scrubbed out the plug and cylinder again. Nice and clean now. It will be a few weeks before I can see if the cleaning makes any difference in the accuracy. Considering there is now a slightly larger volume for the gas to expand into something ought to change.