Cam-pin wear as a contributor to bolt failure?

**WS6** · 07-03-13, 02:23

Does the wear of the cam-pin contribute to bolt failure at the cam-pin hole? I have noticed that cam-pins quickly wear to the point where a fingernail can catch in the wear on the side. Does this peening/wear remove metal from it in such a way as to create more slop and allow more impact/ "running start" for things and end up costing bolt life, if the cam-pin hole is to fail before the lugs in that instance?

**Robb Jensen** · 07-03-13, 07:26

I find that it does. I put a mark on my cam pins so that their always installed in the same direction and replace them every 3K rounds or more often if they're getting really beat up before that time. I haven't broken a bolt since doing that for the last 5yrs. Since I've been shooting ARs I've broken 8 bolts.

**Littlelebowski** · 07-03-13, 08:05

Originally Posted by Robb Jensen

I find that it does. I put a mark on my cam pins so that their always installed in the same direction and replace them every 3K rounds or more often if they're getting really beat up before that time. I haven't broken a bolt since doing that for the last 5yrs. Since I've been shooting ARs I've broken 8 bolts.

That's pretty smart, Robb. I might need to swing by and see how you did this.

**markm** · 07-03-13, 09:34

Interesting. I don't do this and have never broken a bolt.

If I'm reconfiguring a BCG and notice a ratty looking cam pin, I'll rotate it out... but never pay too much attention...

In fact... I intentionally try to keep the cam pin rotating to spread the galling evenly on both sides.

**RMiller** · 07-03-13, 09:40

I started noticing some excessive wear on my BCM BCG's cam pin.

I have a new one on the way from BCM. I think its mostly from lack of lube(used to be AR illiterate). It gets greased like a pig now.

**markm** · 07-03-13, 09:55

Originally Posted by RMiller

I started noticing some excessive wear on my BCM BCG's cam pin.

I have a new one on the way from BCM. I think its mostly from lack of lube(used to be AR illiterate). It gets greased like a pig now.

I used to run grease on my cam pins... I never saw that it stopped that wear. I just dry to have the whole area wet with Froglube and don't think about it anymore.

**WS6** · 07-03-13, 09:55

This also bares mention. I can feel wear on a normal cam-pin at around the 2-300 round mark, it catches a fingernail. I have also gotten some experience with the Rubber City Armory product. The QPQ'ed treatment seems to make the cam-pins much more wear resistant. This might be instrumental in bolt-life of that system.

Further, have you noted that cam-pins which fit tighter in a bolt result in longer bolt-life?