I have been discussing with a friend of mine about the life of a bolt and bolt carrier.  He has completely replaced his upper, selling his old one.  He kept the bolt and bolt carrier to use in his new upper.  The bolt and bolt carrier are made by colt and are in excellent shape.  There seems to be nothing wrong with them.  

He read on this forum that if you by a new upper and barrel to replace the bolt.  Bolt and carrier should last his life time.  If the bolt falls in to spec there should be no reason to change it out.  He insists that it would effect accuracy and reliability.  I tell him no if the bolt is a go then it's a go.  I tell him that his bolt is find, it has 1500 rds on it.  He should get 30,000 more.  He thinks I am crazy. The only thing I suggest for him to do is check head spacing before firing.  

What do you guys think?  

He is the one that's nutz.  1500 rounds?  Still should look and spec out as new.  I would not replace my bolt unless I was having problems.  On my '94 vintage Colt, still looks new, never replaced any parts yet, lost count on number of rounds throught it, problably in the neighborhood of 20 to 25 thousand rounds.  I should problably replace the barrel soon, and maybe the extractor and it's spring, just as preventative maintanance, but it still shoots great.

Absolutely right[:D] I bought 4 GI surp bolt assys during the past year, all of whichwere well used strip offs from M16A1s that were upgraded to A2 configuration.  Three of the four checked out perfectly on all four of my ARs, and the fourth, while it would close on the NO GO gauge would not close on the Field guage.  All of these pieces were perfectly functional.

1,500 rounds is nothing. If the bolt headspaces then use it. The Army dosen't like to swap bolts as a general rule, but if they gauge correctly there is absoutly no reason to buy another bolt.