Check chrome lining inside of a carrier bore for any cracks or machining marks. If surface is not perfectly mirror it will eat gas rings just as you said every 500-1000 rounds.
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I have a BCM carbine upper that doesn't have a particularly high round count (Under 3k rounds I think) that has eaten a couple sets of gas rings now too, the first set was worn out after about 500 rounds. As with yours, it never caused any malfs but was just something I discovered during routine maintenance.
Still on my original rings on my slotty Colt. Dude who taught Colt armorer course said it really isn’t something to get too anal about. But depending on volume of use and carbon; at some point they may need changing. Its not hard and no they don’t need to be staggered but I do it anyways because reasons.
I had to do that to one upper I got that was previously used on a FA lower. Tube too. Easy peasy.
If you need gas rings then G&R has what you need:
https://www.gandrtactical.com/BCM-Ga...s-3_p_105.html
Cheap enough to keep a few sets on hand.
After 15 years, this is what the gas rings looked like, on the LMT enhanced bolt in my test gun. 1 of the 3 rings is missing, 1 is severely deformed (actually fell apart upon examination), which left 1 well worn ring on the bolt. When the bolt dropped into the carrier, there was hardly any resistance.
And it still functioned.
I replaced the rings of course, but it goes to show you the brilliance of the original 3 separate/independent ring design, it offers the most fail safe and redundancy. I would not use a one piece, spiral gas ring. The TDP spec 3 ring setup won't "unspool", it's not something that needs to be "improved" which often does the opposite.
We (FCD) were looking at possibly making improved gas rings, but given how reliable and durable the 3 ring design is, the proposed thicker ring (we'd have 2, not 3) would be more durable than the thinner TDP spec ring, but we'd give up the fail safe provided by the extra ring. Not a compelling reason to mess with the 3 ring design.
Attachment 58888
Every time I shoot my rifles I clean them, and inspect the components. If the gas rings look damaged or too worn out, I'll replace them. But I don't replace them on a set interval.