One for the AR Smiths

Silverlode · Dec 3, 2015

Lots of years and thousands of rounds through quite a few ARs (all semi-auto). I know rings can wear out but I have never seen the likes of this before. This is in a gun with maybe 500 rounds, new assembly, first complete cleaning. The BCG was lubed up prior to use with Mobil One and high temp bearing grease on the rails.
Rings are from a Spikes mil-spec BCG, utilizing a 12.5" DD barrel with carbine length gas system. Can't think of any other specs that might be relevant.
Everything looks normal. Doesn't appear to be rough in BC where the rings contact. Not much carbon fouling, etc. I don't recall disassembling and inspecting the bolt thoroughly when it was put together. Maybe the defect existed from the beginning? Did not fail to function.

Thoughts?

Thanks!

outrider58 · Dec 3, 2015

I'm eager to hear what clandestine has to say. If the bolt and bcg interface smoothly, I would replace all three rings and keep an eye on them. Though the gun will run fine on two rings, you definitely don't want parts flying around the inside of your receiver.

pwoolford · Dec 3, 2015

Was this gun suppressed?

clandestine · Dec 3, 2015

3 possibilities come to mind.

1) The gun is way overgassed and is eroding the rings at an accelerated rate. This is common for manufacturers to overport the gas port so people dont bitch about guns not cycling shit ammo. On a short rifle this is very likely. Adjustable Gas is the meast complicated and most cost effective way to prevent this.

2) The gas rings were cheap and eroded prematurely. If you buy replacement gas rings from a reputable vendor and it happens again, its not cheap gas rings.

3) The Bolt Carrier Bore is machined rough and is eating the rings. This is unlikely as they would all wear more evenly which is not what I see. If this was the case you do not polish anything. You live with it, or buy a new Carrier.

Those rings are toast, dont reuse them even if they pass the carrier weight test. Replace rings in a complete set too, not just one or 2.

clandestine · Dec 3, 2015

pwoolford said:
Was this gun suppressed?

That can be a contributing factor as well. :thumbsup:

clandestine · Dec 3, 2015

outrider58 said:
I'm eager to hear what clandestine has to say. If the bolt and bcg interface smoothly, I would replace all three rings and keep an eye on them. Though the gun will run fine on two rings, you definitely don't want parts flying around the inside of your receiver.

This guy

Silverlode · Dec 3, 2015

outrider58 said:
I'm eager to hear what clandestine has to say. If the bolt and bcg interface smoothly, I would replace all three rings and keep an eye on them. Though the gun will run fine on two rings, you definitely don't want parts flying around the inside of your receiver.

Replaced with JP one piece rings, not used yet though.

pwoolford said:
Was this gun suppressed?

It was not. Just a Kaw Valley linear comp.

clandestine said:
3 possibilities come to mind.

1) The gun is way overgassed and is eroding the rings at an accelerated rate. This is common for manufacturers to overport the gas port so people dont bitch about guns not cycling shit ammo. On a short rifle this is very likely. Adjustable Gas is the meast complicated and most cost effective way to prevent this.

2) The gas rings were cheap and eroded prematurely. If you buy replacement gas rings from a reputable vendor and it happens again, its not cheap gas rings.

3) The Bolt Carrier Bore is machined rough and is eating the rings. This is unlikely as they would all wear more evenly which is not what I see. If this was the case you do not polish anything. You live with it, or buy a new Carrier.

Those rings are toast, dont reuse them even if they pass the carrier weight test. Replace rings in a complete set too, not just one or 2.

Good info, much appreciated. It is a Daniel Defense 12.5" CFH barrel that was purchased with the gas block already pinned in place. Have you ever seen DD barrels over ported from the factory?

clandestine · Dec 3, 2015

Silverlode said:
Replaced with JP one piece rings, not used yet though.

It was not. Just a Kaw Valley linear comp.

Good info, much appreciated. It is a Daniel Defense 12.5" CFH barrel that was purchased with the gas block already pinned in place. Have you ever seen DD barrels over ported from the factory?

The 1 piece is a bad idea IMO.

As far as DD Barrels go, yes they are overgassed IMO. Good Barrels but overgassed.

Silverlode · Dec 3, 2015

clandestine said:
The 1 piece is a bad idea IMO.

As far as DD Barrels go, yes they are overgassed IMO. Good Barrels but overgassed.

I have a number of the 1 piece sets laying around just as backup hardware. Very little experience with them. What might I be in for?

I have 3 of those barrels in use. Looks like I better do some inspecting. No experience whatsoever with adjustable gas blocks.

clandestine · Dec 3, 2015

Silverlode said:
I have a number of the 1 piece sets laying around just as backup hardware. Very little experience with them. What might I be in for?

I have 3 of those barrels in use. Looks like I better do some inspecting. No experience whatsoever with adjustable gas blocks.

The 1 piece units cant reliably be tested. With standard rings you see if the rings can support the weight of the carrier. The 1 piece ones wear in rapidly and will fail the carrier weight test after little use. You have no testing method to know when its time to replace them.

Silverlode · Dec 3, 2015

clandestine said:
The 1 piece units cant reliably be tested. With standard rings you see if the rings can support the weight of the carrier. The 1 piece ones wear in rapidly and will fail the carrier weight test after little use. You have no testing method to know when its time to replace them.

Got it. Thanks for the help.

outrider58 · Dec 3, 2015

SLR adjustable screwed and pinned gas block is your friend. $120 at SLR Rifle works. :thumbsup:

outrider58 · Dec 3, 2015

clandestine said:
This guy

I learned from the best! :thumbsup:

Silverlode · Dec 3, 2015

outrider58 said:
SLR adjustable screwed and pinned gas block is your friend. $120 at SLR Rifle works.

I'll have a look. I have an SLR forend on a 9mm build and really like it, and in addition, their customer service was outstanding.

outrider58 · Dec 3, 2015

Silverlode said:
I'll have a look. I have an SLR forend on a 9mm build and really like it, and in addition, their customer service was outstanding.

Yes, they are good people down there. Just don't spaz out like I did and order a clamp on like I did the last time.

cotman68 · Dec 3, 2015

outrider58 said:
[/B]

Yes, they are good people down there. Just don't spaz out like I did and order a clamp on like I did the last time.

So you think the set screw is better than clamp. That's good to know cause I was going to order one for my new DD barrel.

pwoolford · Dec 3, 2015

cotman68 said:
So you think the set screw is better than clamp. That's good to know cause I was going to order one for my new DD barrel.

pinned>set screw>clamp on

Ifdot · Dec 3, 2015

http://www.righttobear.com/SLR-Rifleworks-Sentry-7-Set-Screw-Adjustable-Gas-B-p/sa7-sm.htm

Best deal I can find, (was $89 during black Friday ) super fast shipping too.

outrider58 · Dec 3, 2015

Ifdot said:
http://www.righttobear.com/SLR-Rifleworks-Sentry-7-Set-Screw-Adjustable-Gas-B-p/sa7-sm.htm

Best deal I can find, (was $89 during black Friday ) super fast shipping too.

Dang! Wish I knew about that deal. I'm keeping the clamp-on for my 20'' precision gun and am gonna buy another set-screw/pinnable for one of my 10.5''ers(the only upper that doesn't have one on it). $99 ain't bad though. :thumbsup:

qorban88 · Dec 3, 2015

I contacted JP a while back about their 1 piece gas ring. They said the 1 piece rings seal better with less pressure, so the carrier weight test is not applicable. They also argued they last longer than 3 piece rings.

One for the AR Smiths

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