This is a discussion on mcFarland One Piece Gas Rings... within the M16 AR15 forums, part of the Rifle Forum category; I was wondering if anyone has tried the one piece McFarland gas ring that replaces the 3 split steel rings/washers on the bolt?
What is ...
This gas ring is included in the SOCOM Reliability Parts Kit for US Special Ops units and will "last the life of the bolt even at maximum rates of automatic firing and the improved seal will make the rifle more reliable in the cold", according to the engineers at the US Navy Surface Warfare Center (Crane, IN) who developed the kit.
I've replaced the factory gas rings as they wore out with the Mcfarland ring on every AR that I've owned for years. I've never had to replace any of the Mcfarland rings - ever!
They do last as long as three G.I. gas rings, if not longer and that is even true in the really short barreled full auto guns. We tell students to use either as their preference, but the McFarland rings are easier to put on without buggering them up.
BTW, one of the last things we do at an Armalite Police Armorers course is to have Mike Gingher or I (depending on which one of us is there at the time) take four or five rifles and deliberately use bad parts to show what malfunctions are from what bad parts. I can't tell you how many times I've used ONE G.I. gas ring that was serviceable (and left the other two out) and the rifle STILL worked fine for semi auto firing. That's not to say I recommend that, but it does show the gas rings are a lot stronger and better designed than they need to be.
I used to use them but when the wife and I went to Shootrite Firearms Academy after her first trip to Balad, I had trouble manually cycling the charging handle when the weapon started to get dirty. I swapped the McFarland ring back out for the original bolt rings and didn't have any more problems. After that, I went back and put the original bolt rings back in all my ARs. I guess I found that while it's a solution to a non-existant problem, it did create a new problem so I quit using them.
I don't know. but my gun has been cycling better with them and i have never had any problem whatsoever so far. I have around 400 rounds through it. brand new gun. The tolerancne was a bit tighter fit in the bolt carrier than the 3 split rings, but all in all it works great for me. I keep my firearms very clean and maintained!!!
I ruined my 3 rings getting the off so I hope I get no troubles :)