Broken bolts in AR-15's, replace on a scheduled regimen?

[His lordship.]

Finished reading the book, The AR-15, by Sweeney, and there was a chapter on broken bolts.  I have never heard of another type of centerfire rifle with "broken bolts", there was a picture of what it looks like.  I was at a gun range in the early 90's and witnessed a fellow with an AR-15 that had either a broken bolt or the carrier, not sure which as I did not know much about those rifles then.  The assembly sheered off a large part, the range masters said it was a lack of lubricant.  The rifle owner went home.

In the Sweeney book he mentions that the military replaces this part after a certain number of rounds are put through the gun.  I don't keep records anymore of the number of rounds put down range on individual guns to keep things simple.  Is this a rifle that should have written documentation for part replacement on a set schedule to avoid inconvenience during a hunt or other?

Thanks.
   

[shvlhead.45]

I started an Army career as a 45B, Small Arms Repairer, where we were authorized to repair of replace very part except the lower receiver, in 1986.  I worked in or around that field till December 2009 and never saw a M16 or M4 with a broken bolt or carrier.  Not saying it can't happen.  Bolts, carriers and barrels don't have a round count requirement but do have a required annual  gauging for headspace, breach and muzzle erosion, barrel straitness and trigger pull along with a function check.

I have seen what happens when round sticks in the barrel and another is fired behind it, upper and lower receivers both destroyed.

Gas rings worn, carrier key comes loose and weapon short cycles.

Carrier key or gas tube damaged or bent and bolt won't lock.

Excessive head space usually results in a ruptured case...

I'd like to see an AR15/M16 platform rifle or carbine where the bolt or carrier broke.  My guess is that the parts were seriously inferiour(sp).

v/r
Shvlhead.45

[Dee]

+ 1 shvlhead.45. I too have see thousands and thousands of rounds ran thru AR15s, and M16s in SWAT training, and other Tactical training, and have never even heard of a broken bolt. As you, not sayin it can't happen, but never heard of it, and would also say, there must have been more to it. I have seen dry 15s and 16s gauld the aluminum receiver and cause the bolt to seize, causing a stoppage, but once cooled and lubed everything went back to working.

[Lloyd Smale]

Ive yet to see one either. The closest ive come is the other day when cleaning the bolt out of one of my ars i dropped it on the cement floor and snapped off the gas block. I even have a 762x39 ar that is suppose to be notorious for broken bolts and Ive put probably at least 3000 rounds of handloads, some on the warm side, and crappy wolf ammo through it so far and its yet to break.