Any way to tell round count on a used Colt and some other questions

[cyclesteel]

I have a couple questions so hopefully you guys have some patience :-)

I picked up a used AR15-A3 (6721) LE trade in last week. I was not going to but I decided at the last minute to go back and pick it up. I tried to get the best one out of the few they had left at the shop. The others had a lot more wear on the outside and internals.

I attached some pictures and was wondering if there is any way to tell round count from the bolt wear. I already took it to the range and it ran fine no problems at all.
I did replace the gas rings when I first got it because it did not pass the gas ring test.

Here are some questions.

The tip of the firing pin tip seems to be dimpled. Should this be replaced?

I just order a headspace field gauge so I can check that when it come in but the rifle ran fine is it still necessary to check the headspace?

I have a bunch of spare parts ( they been sitting around for a few years) Does it matter what brand for parts like the firing pin and cam pin are. I believe the spares I have are Stag (cmt) or should I just order some colt parts. And should I swap them out for good measure.

Do you guys think anything else should be replaced?

Thanks for the help

http://img189.imageshack.us/img189/7493/colt1x.jpg

http://img705.imageshack.us/img705/293/colt2.jpg

http://img218.imageshack.us/img218/7852/colt6.jpg

http://img519.imageshack.us/img519/8900/colt3.jpg

http://img97.imageshack.us/img97/4139/colt4.jpg

http://img299.imageshack.us/img299/8286/colt5.jpg

http://img299.imageshack.us/img299/4645/colt7.jpg

[Marty916]

I am not aware of any meaningful way to determine round count. The amount of wear is more important and from your pics there doesn't appear to be anything abnormal to be concerned about. If it ain't broke, don't fix it. I would suggest running the gun and enjoy it until such time that something may come up.

[bkb0000]

if it was mine, i'd replace the cam and firing pins, gas rings (which you did), just for GP, and keep a spare MP bolt with the weapon. i wouldn't bother headspacing, not that it's a huge hassle, but all this can accomplish is confirming what you already know- the weapon isn't gonna blow up by firing. brand doesnt matter, so long as you use a respectable manfer.. CMT is good to go.

aside from that, loob, shoot, enjoy.

[DaBears_85]

Whoever cleaned that bolt face did a pretty good job.

Looking at pictures and inspecting it by hand are two different things, but it all looks pretty good. You should be fine.

[Ridge_Runner_5]

I'd say just about 142 rounds have gone through that weapon...and the person cleaning it has OCD.

[cyclesteel]

I'd say just about 142 rounds have gone through that weapon...and the person cleaning it has OCD.

That is the exact number I was thinking.:D

Thanks for the replies. I was starting to get a little buyers remorse and thinking I should have bought a new 6920 or Noveske but the price was right on the 6721 and I really did not need another AR but you know how it is.

As for how clean the bolt was. 2 of the 6721’s at the store where that clean and the other had the carbon caked on. I lubed it with a good amount of Weapons Shield when I got home and went to the range and ran a few magazines through it. All’s I did was wipe them down before I took the pictures ( I love Weapons Shield BTW )


Guys thanks again for the help. It is always appreciated.