I put one on the bolt that came with my new Accuracy International 1-8 twist stainless service rifle barrel. I have always used stock with no problems, but I thought I'd try one - will report later.

USMC03 I use one only because the org. rings or one of them bent over and was riding sideways in my eagal arms action master in less than 1000rnds .I contacted Eagle Arms and they made the recomendation for McFarland that was 8 yrs ago and 4000 rnds later still functions but I notice it seems a little sloppy. Good luck! gj
           www.moaammo.com   [frag]

They work on full auto just fine. My rate of fire is about 950 RPM even with the McFarland rings. They're kinda tight at first but seem to work in just fine.

I use them in my AR's and have put them into friends AR/M16s.

Yes they work.

How long do they last . . . don't know, haven't worn any out yet. [:D]

Why use them . . . It's possible that the gaps in the stock gas rings can line up and cause a malfunction.  Yes, I've seen it happen, but not since I started using the one piece gas rings.

Look for the topic "GOT BACK FROM THE RANGE & LOSING FAITH IN MY AR's"
(about 2-3 weeks ago) I posted this topic, asking for advice on how to get my AR's to function 100% again...
I had installed these Mcfarland gas rings in 2 of my AR's.
Both guns worked "OK" for 5-6 mags worth of ammo. Near the end of my day at the range, I started to notice cycling trouble with the guns. (both of them) I just figured they were dirty after 150-180 rounds of semi/rapid-fire shooting.
So, I took the guns home and thoroughly cleaned them...
The next weekend at the range was a disaster...both guns gave me all kinds of trouble(short cycling & skipping over rounds). I didn't even consider the gas rings because they were brand new...BUT, after advice from folks here at AR-15.com,  I decided to install my OLD wore out 3-piece gas rings back into the guns...
Next trip to the range I beat the snot out of both guns and was amazed at the difference in reliability...

gun # 1- (Olympic w/Colt HBAR) 100% reliable 6 mags 0 jams

gun # 2- (Carbon-15) had extracter problems unrelated to gas rings, but NO more short strokes...  
 
(I've since traded gun #2) but have since put at least 300+ rounds through gun #1
with the OLD 3-pce gas rings and still 0 failures...

I think if these McFarland gas rings were worth a shit, the military would have them in ALL thier guns...

They're only $1.75 each, so you haven't much to lose if you decide to try them anyway...

I just had a bad experience with them...  

I tried them on some Les Baer chrome bolts & had a problem with short stroking also. They worked fine at first but after running a few clips I believe the heat affected the rings causing them to expand. Les Baer's bolts are made to max milspecs, IIRC, & the rings don't have the room to expand length ways so they expand outwards, causing more friction, hence short stroking.

COLTSHORTY

GOA KABA COA JPFO SAF NRA

"I won't be wronged,  I won't be insulted
and I won't be laid a hand on. I don't do
these things to other people and I require
the same from them."

I've had the McFarland rings in two AR's for a couple years now.  Cleared up the occasional problems I had in the past experienced in these two weapons with the gas rings rotating around and allowing leaks. Both the Colt and the Bushy are a LOT more reliable now(Wish I'd had one back when I was using an M16, lol).  Haven't noticed any wear or other problems so far, but then they're cheap and simple to replace if necessary.


                [sniper]

I have one that I took out of my dissapater and went back to the standard 3 rings.  

My NM has the standard rings also.

I've never had a problem with the ring slots lining up and causing a malfuction, nor have I ever see/heard of such an event at any match I've been at.

The best "add-on" part I've had experience with for ARs is the "Dfender" extractor spring booster, a simple blue polymer "D" Ring that goes around the extractor spring. I used to replace the extractor springs every 2K rounds or so, then installed this Dring doodad and am going on 6K of mostly full-auto fire w/o replacement of the extractor spring. A great product. D.