hoppes will probably work if you soak it in.
if not you can probably use transmission fluid.
or CLR cleaner.
maybe... I don't know that I would want a power tool in it.
you can buy new ones for not too expensive though so if you mess it up it shouldn't be a big deal to replace it.
I can certainly pick one up for $15. That's not the problem. This is more of an education for me. I figured if I can get this crap off, then I'd feel more confident tackling other rust problems (say, a gas block).
This gas tube was from a recently acquired bulgarian AK-74. The previous owner shot corrosive ammo and did not bother to clean the gas tube. Fortunately, it was the only casualty. Everything else looks clean. Probably has to do with the chrome-lining (barrel, gas block, muzzle brake).
I tried the following method and did not help any, except remove the carbon buildup.
- wash all the corrosive salts with hot water, then dry (tried windex too)
- soaked in brake cleaner (more to remove the carbon)
- soaked in CLP
- elbow grease with brass and nylon brush
- wiped with Eezox
My thought was that I was not going deep enough and the corrosive salts are baked in there underneath all that gunk that I could not remove. No matter how much lubing and chemicals I put, it just comes back up after 24 hours.