Cracked cam pin (Ruger AR-556)?

M

MisterYuck

New member
I took the bolt carrier apart last night on my AR-556. While I was wiping the cam pin down I saw what looked to be excessive or odd looking wear patterns. Upon further inspection, I think it my be cracked or somewhat fractured or distorted. I have maybe 500 rounds through this rifle. I have had it for just over a year. I have had no problems with it at all. I do not rapid fire it to see how fast it or I can shoot. I do not use a bump-fire stock or a hand crank or any other gizmo to make it shoot fast. I keep the BCG cleaned and lubed. Is this unusual? Will this thing break? I am afraid to fire it until I hear something. I will post photos soon.

Thanks!
 
Last edited:
Cam pins, and their respective slot through the bolt, take a lot of force. It is usually the bolt cam pin slot that breaks, but only after 10s of thousands of rounds unless it is a crap part. If what you see is a curved line in the pin near the shoulder, that is typical.

Rate of fire has nothing to do with the force, just the number of cycles. A thicker lube, or even grease on the cam pin is beneficial.
 
Here are the pics.
 

Attachments

  • campin1.jpg
    campin1.jpg
    96.8 KB · Views: 178
  • campin2.jpg
    campin2.jpg
    73.9 KB · Views: 158
  • campin3.jpg
    campin3.jpg
    79.3 KB · Views: 142
That's not a crack, it's just barely getting through the phospate finish. But either way, cam pins are an expendable part, they cost less than $10, and you should keep one on hand in your spare parts. Same for gas rings, firing pin retaining pin, takedown detent springs, etc, keep a spare one on hand.
 
All of mine look like that after a couple hundred rounds, never yet had one break but it's one of the things I keep a spare of in my kit. I do use a dab of grease on it when reassembling, but can't honestly say that it's made any difference in the wear pattern.
 
Its tough to say, the first pick shows what could be delam or just finish flaking off at the shoulder of the pin. When in dought just replace the pin, it is a cheap part. Just install the new one and watch it for any strange wear. What is your experience level with Ar's? The reason I ask is to see if you have any others to compare to?"
 
This is my first and only AR. I have not taken any others apart so I have nothing to reference. I found a "Roller" cam pin online for $23 and I wonder if it is a worthwhile investment.
Thoughts?
 
I would not suggest the roller cam pin on a .223/5.56 AR15. I use them on the heavy recoiling ones, like .450BM and .458Socoms.
 
Juice is not worth the squeeze. No detriment on a .223 at all, just no real benefit in the softer recoiling .223. Their main benefit is to reduce wear on the upper receiver and .223 uppers will last for many barrels worth. I have one with over 100K on it and there is minimal wear.

In the heavier recoiling calibers in the AR15, you are pushing past the original design intent and while there is still a good factor of safety, the wear will increase. I have seen a few of the heavy caliber uppers that were trashed after about 15-20K. Sure, that is a lot of rounds, but the roller cam pin reduces the wear on those.
 
Thanks for the info. Kinda like putting a roller cam and roller rockers in a stock 1974 Chevy Nova with a 305 V8 to go get groceries with.
 
If there is a ridge that can be filed down to flush and then buffed smooth with crocus cloth. I have done that. Replacing cam pins is cheap. Might call Ruger and tell them about your cam pin. Maybe they will send you a new one.

I do recommend using a light grease or LSA on the cam pin.
 
You must log in or register to reply here.
Back
Top