Never had it happen with a ML, way back when (Aug 75) I was on the wrong end of a hot barrel change of an M60 mg. My platoon was qualifying our M60 gunners, we had 1 per rifle squad and the assistant gunners. Also had the lift platoon, the UH-1 door gunners and crew chiefs were firing. The barrels were right at the verge of slumping, started pulling guns off the line to cool and change barrels. Two of us started to change barrels, as we pulled the gun apart, I saw a round still in the chamber. I called out, just as it cooked off. Both of us transported to the hospital at Ft. Carson, where Drs. picked out micro-pieces of brass and powder out of our faces for hours. I catch the primer in my right shoulder, so I took even longer to clear. My Platoon Leader went my home and got my wife, who was +8 months pregnant, and brought her to the hospital. She had our first son about a week later!