I was wondering how ARs wear out.
   Obviously there will be small parts failures and barrel wear, but what is the the major structural wear after, say, 70,000 rounds? Do the trigger group pin holes become oversized? How about the takedown pin holes? Does the interior of the upper wear, so that the bolt carrier is loose inside it?
   How does an AR wear out to the point where parts replacements cannot help?

              CA

all in ghow the rifle is cared for.

I'm no armorer and I'm sure one will pop in, but I've seen a lot of M-16's in my Army days.   As above, it is all how it is cared for.  With methodical maintenance and careful handling they can go indefinately.  The upper/lower fit will get quite loose as the steel pins bang against the aluminum recievers to the point where you may not even want to shoot it.  The barrel will wear to the point of considerable loss of accuracy.  The recievers, however can just keep going and going. . . .

Has anyone seen the pictures of trhe M-16's they conficate from Phillipino guerillas now and then?  Bright, shiny aluminum from decades of wear.