one-piece gas rings and M4A1
Hi, folks. First post here.
Have a question on the McFarland rings. I've installed McFarland rings on several Colt M4A1's and without fail, the rings provide little to no tension inside the bolt carrier. After installation, the bolt will readily collapse inside the carrier if the carrier is inverted. Thus, I've been unable to use them and have had to replace worn rings with the three-piece arrangement. For what it's worth, the bolts have seen anywhere from 3500-7500 rounds down the barrel. Do any of y'all know if this is something particular to the M4A1?
I'd appreciate any information on this.
Thanks.