Any idea why this happened?

[NewbieAKguy]

OK, this past Aug. 16 I did my local range's monthly 3-gun shoot and decided to finally use my AR (only used my "manly" rifles before: ptr91 or Garand). The only times I had shot my AR was the recommended break-in process from dpms and another time to confirm my sights......Remy UMC .223 was only used. Well for the shoot I wanted to try some wolf 55gr hp and BB 55gr fmj i had and to see how it did with steel cased ammo. As far as I could tell it ran without a hitch....i shot about 20-30 rounds of wolf and about same for BB. Well got home and cleaned her up and found that one of the gas rings on the bolt had become damaged. Instead of the normal gap in the ring (no idea what gap is) the ring closest to the lugs had broken a chunk off and opened up to roughly 1/8". I tried to take a pic but my camera won't zoom in far enough to take clear pic.

How worried should I be? The broken ring possibly caused by using steel cased ammo? Showed couple guys I know who are more familiar with ARs than I and the both pretty much said to shoot it as it is until it causes failures...or just get new bolt and/or rings.

What say yous guys?

[imanaknut]

With the cost of replacement rings so inexpensive, I would replace all three. There is always the possiblilty that the ring will continue to fracture and it could cause damage to the inside of the carrier.

Only if you are sure that it won't break any further, and there are no sharp edges to damage the carrier, then go ahead and fire the AR as long as it functions properly.

I seriously doubt ammo caused the ring to break.