We had night fire training the other night. We were training at the 12 yard line with automatic fire on shoot- no shoot targets. I had a malfunction that I promptly attempted to clear. The bolt was forward but not in battery. When I ran the charging handle I though I saw a live round eject but it was dark, had three cars with sirens blaring, flashing LED and strobes all around me and I was on the move so I wasn't 100% sure. After getting back on the trigger I had no hammer drop. Transitioned to my sidearm which I should have done first BTW. 
We run "A Hot Range" so all guns are kept loaded and topped off at all times. Once I had the time I checked my rifle and found the bolt was forward on a live round but the bolt was out of battery. I dropped the mag and ejected a live round. The bolt would not go into battery on a empty chamber. Figuring I had a chunk of brass, primer or other debris in the locking lug area I shined my light inside and noticed a small piece if something in there.
Ended up benching the gun and tearing it down. It ended up being a sheared off locking lug. In 30+ years of shooting the M16 this was my first. I replaced the bolt with a spare, checked the head space and finished my firing problems.
The gun is a 14.5" SOCOM barreled Colt M16A1. The gun is a 6 digit serial numbered very early model marked XM15E1. I rebuilt it three years ago and modernized into a M4. Everything on the gun is Colt manufactured as best as I can tell. During re barrel the bolt was reused and head space checked fine even though it was a well worn bolt and a new Colt barrel. By my log book this gun has 7250 rounds since rebuilt, mostly TAP in 40, 55 and 75 grain . No telling how many on the bolt but many, many more then that.
All in all a non event but I thought I would share. I took some pics but my camera is in my trunk and to lazy to go get it. I will post them later if anyone is interested. And that is pretty much that..sheared locking lug on a M16.
We run "A Hot Range" so all guns are kept loaded and topped off at all times. Once I had the time I checked my rifle and found the bolt was forward on a live round but the bolt was out of battery. I dropped the mag and ejected a live round. The bolt would not go into battery on a empty chamber. Figuring I had a chunk of brass, primer or other debris in the locking lug area I shined my light inside and noticed a small piece if something in there.
Ended up benching the gun and tearing it down. It ended up being a sheared off locking lug. In 30+ years of shooting the M16 this was my first. I replaced the bolt with a spare, checked the head space and finished my firing problems.
The gun is a 14.5" SOCOM barreled Colt M16A1. The gun is a 6 digit serial numbered very early model marked XM15E1. I rebuilt it three years ago and modernized into a M4. Everything on the gun is Colt manufactured as best as I can tell. During re barrel the bolt was reused and head space checked fine even though it was a well worn bolt and a new Colt barrel. By my log book this gun has 7250 rounds since rebuilt, mostly TAP in 40, 55 and 75 grain . No telling how many on the bolt but many, many more then that.
All in all a non event but I thought I would share. I took some pics but my camera is in my trunk and to lazy to go get it. I will post them later if anyone is interested. And that is pretty much that..sheared locking lug on a M16.
