I carried and used an M60 for the first 5 months of my tour in RVN. I was handed it the first day in my unit as that was how a gunner got rid of carrying that 26 pound thing in the heat. That same day I was sent up with a Sgt. to knock out a sniper in Cho Lon which was the Chinese section of Saigon. We had to crawl in a drainage ditch filled with sewage (human type). We got up in position and the M60 would only fire once, then jam. Lift the cover, clear, load the belt and fire one round. Start all over for your single shot machine gun.
After a good cleaning, the first it may have seen for a while, it worked when called upon on in the following months. I never trusted it though and always glad I had a 1911 as a back up. The photo is sometime between March 68 and July 68.