TexasCHLforum.com

Really wouldn't surprise me. I've seen soldiers grind their bolt-face on concrete to break up the carbon. "Cleans faster this way, Sarge!"

On the cleanliness bit, I never once subscribed to the white-glove nonsense (and never once saw a rifle that was spotless). Nor did I ever have a malfunction caused by anything but a magazine (and I forced that to happen to illustrate why the magazine is not a grip). This was true for my rifle, or those of anyone on my ranges. Most stoppages were the result of soldiers using the magazine as a forward grip and pulling down and back on it - causing a failure to feed. I did see an extractor get lost once... that was interesting. My rear sight fell off on a particularly ancient A2 (as did the dust cover). Didn't keep it from cycling though.

In sort, solid chunks of garbage are bad - they don't belong in your weapon (regardless of what it is). So is a ton of oil.

Never actually managed to get a round stuck in the pipe, but I imagine the advice here would work.