How many rounds can a bolt assembly take before it needs to be replaced.  Do the individual parts of teh assembly wear differently?  

How long can barrel/chamber last?

About 10,000 to 13,000 is about it.  I have one M16 that has 60,000 rounds on it and has worn out quite a bit of stuff.

I had one barrel that I had run a little over 10,000 rounds and it still shot 1" groups at 100 yards.  I never checked it on paper again until it had about 13,000 on it, and at that point the bullets were tumbling.  The headspace continued to lengthen and at about 10,000 it would have case head seperations if the ammo was sized to minimum dimensions.  The most notable wear on the bolt is on the face itself where pits appeared around the perimeter of the primer.

No pits on the bolt face, but I did have an extractor failure after 10,000 rounds.  Carrier does look a little worn, but no worse for wear.  The carrier key does have some flat spots on it, but it still looks pretty solid.


Everything else seems ok, but I am changing the upper.  I'm doing some major upgrades to my rifle, so I figured I would part the upper and dump the barrel.