I'm not usually one to stray from original parts in my guns, but I did use KNS anti-roll pins, D-Fender, and H buffer / ISMI recoil spring in my build. I also use MagPul followers in teflon mags...so maybe I'm not so innocent.

Anyway I have been tossing around the idea of using different gas rings and firing pin retainer pin. Does anyone have a pic or good description of the RRA gapless and 1 piece McFarland gas rings? I've seen the KNS perma-pin replacement for the FPRP, but what I don't get is how it keeps enough friction in the carrier, and if it increases long-term wear in the carrier. Thoughts? Which gas rings do you prefer?

Oh yeah, where's the best place to get these items?

One piece gas ring and KNS FPRP contact CMMG the KNS pin has a split in the end of it that is expanded somewhat to hold friction. looks just like the EARLY retaining pins... I do not foresee any additional wear due to that pin or the one piece ring.

Thanks man, found them at PK Firearms...think I'll go ahead and order. Wasn't sure between gapless and 1-piece, but the McFarland doesn't seem to have any issues so...

BTW, how do the gapless rings work?

I installed the one piece gas ring on my AR. If i kept it 'very well' lubed it ran fine. Im talking generous lube every 100 rounds. If not it turned my AR into a 'jam-o-matic'. I swiched back to the original rings and it ran like a champ. It might work for you and then again it might not.

Really...too tight or? Is that why RRA decided to use 3 piece gapless?

I think that the one piece rings are an answer to a problem that did not exist...

If you do not have any problems with the 3 rings, why switch?

I just don't want to have to worry about one breaking and it'd be nice to avoid the hassle of having to line them up each time I clean the bolt. Any tips on install?

the rra rings have fat ends so that there would be no room to "line up"


i bought some of the mcfarlands to see what it was all about and have to say this, i had no problems before with 10krds had no problems afterwards.

Got both the 1 piece gas ring and the KNS Perma-Pin. The McFarland gas ring was a lot "tighter" than the USGI rings, so I manually cycled the bolt about 300 times to help seat the rings since this is about how many rounds the rifle has seen so far. I cleaned the rings and chrome lined carrier twice during this break-in period and there was plenty of dark grey grit that looked like the HC finish in there. It smoothed out real nice and I don't expect it to be a problem. Just wonder how USGI rings would work now though if I had to switch back.

Note, the USGI rings weren't fully seated yet judging by the polished appearance of the ring edges, but there wasn't much friction in there after such a small amount of use.

The KNS FPRP was a BITCH to install the first time. I used lots and lots of Mobil-1 and it was still a bitch. Thought it was too large for the carrier some how. Finally, I decided I didn't care if the prongs broke off as warned about in the instructions, and I FORCED it in there. No problems and it works great now...now I don't have to worry about the cheapo cotter pin walking out and scraping my upper. Everytime I've pulled the BCG out it has been backed all the way out that it can while in the upper.

These mods may be getting picky as hell, but I just consider this my "high-reliability" build. No cost is too great for this already outrageously expensive "toy". Now to add a $300 + EOTech and who knows how much for a mount.