Have you taken any measurements on what the issue is?While i consider Rugers AR's to be extremely substandard, by far the single worst component on them is their bolt carrier group.
I have seen so far 7 different Ruger AR's exhibit the same issue where a gas ring partially jumps the slot, and wedges the bolt partially out of battery over the past few years.
They are piston rings. The standard ar15 has an internal gas piston formed by the tail of the bolt, and the internal bore of the carrier. Gas flows into this chamber and expands, pushing the bolt forward, which kicks the BCG back.Have you taken any measurements on what the issue is?
Several things could be going on here.
Bore in the carrier too large.
Diameter of the bolt where the snap rings go (yes, those are snap rings, not piston rings).
Possibly the rings too soft.
Have you tried a McFarland style ring? (the spiral, one piece type)?
That is the only type of ring I will put on an AR bolt, there are no thin spots around the circumference.
@zackmars
They are snap rings, just look at the profile, they are just missing the holes for snap ring pliers.
Every time they fail, it is at the thin part of the profile.
If that wasn't there, the failure rate would go way down.
McFarland rings don't have that thin point, and they never fail.
If the wana-be piston rings didn't have those 2 thin points, they would be piston rings, and wouldn't be failing at the rate they do.
The reason for Armalite/Colt/ everyone else still use this crap is understandable if you read my signature.
Yeah? Well my urine is red, so take that!And I can write my name in piss on a wall prettier than all you bastards.
<>While i consider Rugers AR's to be extremely substandard, by far the single worst component on them is their bolt carrier group.
I have seen so far 7 different Ruger AR's exhibit the same issue where a gas ring partially jumps the slot, and wedges the bolt partially out of battery over the past few years.
Fixing the problem involves pulling back the CH till the bolt locks about halfway back, separating the upper and lower until you can get a screw driver in the forward assist scallops, and driving it forward with a hammer till you can use the FA itself. Once it is in battery, you can fully remove the lower. Unlock the charging handle, have the upper in a vise (or have a buddy) hold it upside down, and stick a thick screwdriver against the back portion of the BCG, and hit it with a hammer. Hard.
With the carrier out, you should be able to remove the cotter pin and firing pin just fine. You will need to beat the bolt into its locked position by placing the BCG vertically and hitting it hard with a hammer. When that is done, you'll need to rotate the cam pin 90°. I've found a pair of needle nose pliers work the best. You'll then need to pull the cam pin out. Any slip joint pliers work well. You can then use a .30 caliber ram rod in the backside of the carrier to pop the bolt out. This beats up on ruger's cam pin pretty hard, and I would recommend replacing this part.
Typically it's only one of the 3 rings that has jumped, the other 2 are usually fine. Replacing all 3 rings will not solve the issue. Fortunately the AR really only needs one ring, so removing one of the rings will at least get you an extra mag or two of shooting if you really need it.
I believe 1 (or multiple) of 3 things are happening. Ruger's bolts are undersized, the carrier's bore is oversized, or the slot the rings sit in is too shallow.
The only real fix is to buy a higher quality BCG, Colt, BCM, DD, RRA, PSA, hell, even Anderson. These BCG's are also far easier to disassemble since the cut out for the cotter pin is properly shaped, unlike ruger who just cuts a flat spot.
You can always contact ruger for a new one, but it'll be a similar BCG to what you already have, from the same production line, with the same (at best) batch QC checks.
I'll see if I can add some pics later, but damn ruger. It's an AR BCG. The only thing that's easier to make is an A2 pistol grip.
The SFAR? I don't like the design of the BCG, but i haven't seen any issues with them so far.<>
Thanks for posting these details. Although long associated with AR’s, from the US Army days of “Stoners” adaptation, my knowledge is very superficial. I’ve owned a BushMaster AR15 20+ years, but doubt if 200 rounds fired.
Could you say if this problem also affects the new .308 Ruger AR ? I was looking to buy a new one.
Thanks again, leVieux
If you check on the Ruger forum there have been some first production issues. I recommend waiting a bit to let them get the bugs worked out.<>
Thanks for posting these details. Although long associated with AR’s, from the US Army days of “Stoners” adaptation, my knowledge is very superficial. I’ve owned a BushMaster AR15 20+ years, but doubt if 200 rounds fired.
Could you say if this problem also affects the new .308 Ruger AR ? I was looking to buy a new one.
Thanks again, leVieux
<>The SFAR? I don't like the design of the BCG, but i haven't seen any issues with them so far.
I'll start liking ruger once they figure out why their QC department has disappeared.Zackmars loves ruger.
Who needs a QC department when everything these days is made on CNC machines?
Just push a button, and you get the finest machine work ever!
Manufacturers should put on the sn what day of the week a gun was made.I'll start liking ruger once they figure out why their QC department has disappeared.