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ArcticMan
10-31-09, 16:54
I have noticed heavy wear on the bottom of my Colt Bolt Carrier. The carrier is a non-shrouded carrier and there is even wear on the firing pin that is exposed.

I have another Colt (6920 that I purchased this spring) and it has a fully shrouded bolt carrier that has absolutely no wear issues.

Since the the bolt carrier that has the excessive wear on it is about 10 years old and non-shrouded I assumed that I wasn't the only one with this problem.

I went to the local dealer and told him about my problem. I was surprised to find out that there were a few others in my area that had the same issue with the non-shrouded bolt carrier.

The dealer contacted Colt and sent in one of the bolt carrier groups (this one had chipping as well as excessive wear). After 6 months of working with Colt, they replaced the bolt carrier, but stated that the wear was "normal".

My bolt carrier doesn't have any chipping...yet. To be honest I can't say that it will ever start to chip. But I have been shooting M16/M4s for over 20 years and I don't see this wear on the bolt carrier as "normal".

Have any of you guys noticed any excessive wear and chipping issues with your Colt bolt carrier groups?

Also I don't know if this is related but I noticed that on Brownells.com that they no longer sell the Colt bolt carrier group as the "manufacture has discontinued this item".
Robb Jensen
10-31-09, 17:51
Some wear there more than others. It really depends on the roughness of the finish on the hammer. The bolt carrier is what cocks the hammer.

RRA polishes this area of the carrier all the finish is removed. I'm sure they do this because customers were complaining of wear there.
d30gaijin
10-31-09, 18:48
for the non-shrouded carrier from my experience.
Blankwaffe
10-31-09, 19:06
Yeap the unshrouded SP-1 type carriers were something of a,well crappy idea that was politically driven and some were coby and half ars machined to boot.If you do a search there are a few pictures of dinged up and worn examples posted here.
Ive got one Colt patent marked SP-1 type carrier remaining that came in a early model Armalite that has the wear you mention.Personally I think alot of the dings and wear I see on the ramp of that carrier is due to poor machine work.
Other issues Ive noted and complained about over the years in regard to the unshrouded carriers has been excessive wear to the firing pin spool and in most cases the firing pin retaining pin is bent in the process.First AR I owned spit the firing pin into the action when the FPRP failed at about 700 rounds due to the related hammer and firing pin spool contact.
All the rifles that I had/have that used the unshrouded SP-1 type carrier I replaced with a fully shrouded carrier as they came available.Nowadays the shrouded carriers are the norm,so its no longer an issue.
IMHO if I were you I'd replace the unshrouded carriers with a proper in spec shrouded carrier such as what is offered by BCM and G&R Tactical for $79.00.Its a huge upgrade for the money,and greatly extends the service life of the related components.
Eric
10-31-09, 19:36
Normal wear for that configuration, but frustrating nonetheless.
Not the best pic, but you can see wear on this one from a 6721.
http://img.photobucket.com/albums/v503/AR15forme/Colt%20AR15/P1010114.jpg
Blankwaffe
10-31-09, 19:39
You da man Eric.
Perfect example.
cz7
10-31-09, 20:12
Normal wear for that configuration, but frustrating nonetheless.
Not the best pic, but you can see wear on this one from a 6721.
http://img.photobucket.com/albums/v503/AR15forme/Colt%20AR15/P1010114.jpg

now that is p/c Q.C. at its best! new bolt carrier is needed - i wonder if this works other parts like the hammer as well or break pins too ??
Quib
10-31-09, 21:22
This un-shrouded carrier of mine had about 6,000 rds through it before I swapped it out for a shrouded carrier. It did like to leave the FPRP a little beat up, but it never came to a snapped FPRP. I did change the FPRP out a couple times though.

Comparing my pic to the pic above, it appears my carrier exhibits some mild wear on the ramp, a bit similar to the carrier above.

http://img.photobucket.com/albums/v489/Metroliner/carrier.png
Blankwaffe
11-01-09, 01:02
This un-shrouded carrier of mine had about 6,000 rds through it before I swapped it out for a shrouded carrier. It did like to leave the FPRP a little beat up, but it never came to a snapped FPRP. I did change the FPRP out a couple times though.

Comparing my pic to the pic above, it appears my carrier exhibits some mild wear on the ramp, a bit similar to the carrier above.

http://img.photobucket.com/albums/v489/Metroliner/carrier.png

Quib,
That carrier you have there is alot better quality than the one that came out of my old A2.The one I have looks like the one Eric pictured.
I probably should have added that the root cause to such early failure of the FPRP in my case was an out of spec hammer notch(and a poor PM and inspection routine which has also been corrected) that was diagnosed by Tweak a few years back.At that time it was recommended to use the shrouded carrier which also negate the hammer issue.
ArcticMan
11-01-09, 02:10
Yep. My bolt carrier looks like the photo that Eric provided.

I don't see Colt doing the right thing and replacing it on their dime. I don't think it is a stretch to say that the problem with the bolt carrier is the poor design and nothing the user did.

Thanks for your guy's replies they are most helpful.