@cmshoot, Is this excessive bolt cam pin wear and should I replace it?

[palmettomoon]

cmshoot I've read a bit on the innerwebs and I'm curious as to your opinion on the matter. I'm shooting a home build AR 15, pencil barrel 16", SJC comp, JP Silent Capture Buffer/Spring, JP reduced mass Bolt Carrier, GI MPI bolt, GI firing pin. Mostly 55 grain ball ammo but IO do shoot 77's (handloads @2,425 fps) out to 600 yards for 3-gun. The rifle is great, lightweight, etc., and I'm using a Riflespeed adjustable gas block. It's consistently 1.75 MOA at 600 yards and that's fine, all I have to do is hit a 2/3rd scale IPSC steel silhouette.

My question is, now that I'm through bragging on my boom stick, what defines excessive bolt cam wear to the point where YOU'D replace one? I do NOT want my BCG to fail during a match so I'm trying to get ahead of this issue, if it is in fact going to BE an issue. I carry a large container of all kinds of spare parts when I attend a match so I could repair it as long as I can get the BCG out of the rifle, but if a $10 part is all I need to swap before a failure, I believe in the old "ounce of prevention" thing.

The cam pin on the left is the one in question. It's been scoured or worn so that the hole pattern from the BC is evident to the point of catching a pick or a fingernail. I do not see any incipient cracks under magnification, but that doesn't mean it isn't about to fail. What's your opinion? I had cam pins like this on old M16s at Bragg but never gave it a second thought as the Army would give me another one when they thought I needed one.

Would you replace this? I have new pins (pictured for comparison) at hand.

Thanks

 

[thejacksonharris]

cmshoot I've read a bit on the innerwebs and I'm curious as to your opinion on the matter. I'm shooting a home build AR 15, pencil barrel 16", SJC comp, JP Silent Capture Buffer/Spring, JP reduced mass Bolt Carrier, GI MPI bolt, GI firing pin. Mostly 55 grain ball ammo but IO do shoot 77's (handloads @2,425 fps) out to 600 yards for 3-gun. The rifle is great, lightweight, etc., and I'm using a Riflespeed adjustable gas block. It's consistently 1.75 MOA at 600 yards and that's fine, all I have to do is hit a 2/3rd scale IPSC steel silhouette.

My question, now that I'm through bragging on my boom stick, is what defines excessive bolt cam wear to the point where YOU'D replace one? I do NOT want my BCG to fail during a match so I'm trying to get ahead of this issue, if it is in fact going to BE an issue. I carry a large container of all kinds of spare parts when I attend a match so I could repair it as long as I can get the BCG out of the rifle, but if a $10 part is all I need to swap before a failure, I believe in the old "ounce of prevention" thing.

The cam pin on the left is the one in question. It's been scoured or worn so that the hole pattern from the BC is evident to the point of catching a pick or a fingernail. I do not see any incipient cracks under magnification, but that doesn't mean it isn't about to fail. What's your opinion? I had cam pins like this on old M16s at Bragg but never gave it a second thought as the Army would give me another one when they thought I needed one.

Would you replace this? I have new pins (pictured for comparison) at hand.

Thanks

Just curious, legit question, why wouldn't you replace it and start working it in just to make sure and be positive you won't run into any problems? Preventative maintenance.

 

[bambam]

These antique design firearms have a plethora of problems that have never been fully addressed in their over 50 year history. Just get another one from JoeBob.


https://www.joeboboutfitters.com/Rock-River-AR-15-Bolt-Carrier-Group-Cam-Pin-p/rra-ar0031.htm

 

[palmettomoon]

These antique design firearms have a plethora of problems that have never been fully addressed in their over 50 year history. Just get another one from JoeBob.


https://www.joeboboutfitters.com/Rock-River-AR-15-Bolt-Carrier-Group-Cam-Pin-p/rra-ar0031.htm

Already have two at hand plus a dozen in spare BCGs but you know me man, I can get a dime to come out betwixt two pennies when I squeeze them hard enough.

 

[joel2000]

Man… I know zilch about the consequences of the wear you’re showing but,
I’m in the WTH $10 dollar replace it club.

 

[palmettomoon]

Man… I know zilch about the consequences of the wear you’re showing but,
I’m in the WTH $10 dollar replace it club.

I did, was curious to read cmshoot's opinion though.

 

[bambam]

How many rounds it take to do that?

 

[joel2000]

I did, was curious to read cmshoot's opinion though.

Love all these posts on all things AR. I learn so much and the varied opinions.

 

[palmettomoon]

How many rounds it take to do that?

I don't know that it wasn't a used bolt cam pin when I installed it so I couldn't tell you. I don't keep a log book on the 3-gun rifles like I do High Power but 500-1,000 rounds would be a good guess.

 

[Hayata]

What kind of lubrication do you use on your cam pin?