ARMS or Leupold losing POI?

tank1949 · January 16, 2020, 10:16 AM

I am having issues with my Leupold Mark 4 M1 or the ARMS quick release rings holding POI. A just installed them onto a new RR X-1, 308. I hand weigh charges, use only FC 308 hulls and CCI LR primers. Yet, my groups go from sub MOA to 3 MOA from 10 shot groups to 10 shot groups. I mainly shoot 41 grains of 8208 or 40 grains of AR Comp and 168 SMK bullets. If the RR was a bolt gun, I'd first suspect a bedding issue. A few years back Leupold replaced my Mark 4 with a new one after identifying internal spring problems causing similar issues. Now, the similar issues have returned. However, perhaps the ARMS quick release are not strong enough to maintain consistent MOA groups on a 308 and only suited for .223 rifle recoil. I have Warne quick release rings on my SA M1A that provide a rock solid mount system. No POI change!!! Has anyone has issues with ARMS quick release rings on 308s??? My next option is to change scopes and use Warne rings. However, unnecessary range visits are both expensive to my pocket book and to my shoulder. The shoulder is the worst!

NoSecondBest · January 16, 2020, 10:25 AM

I own two of those scopes and one of my friends has a couple. Neither of us has ever had a problem. He's using one on a .338 Laupa and a couple of AR's. I'd try another scope and see what happens. That will quickly rule in/out if it's the scope. Even Leupolds can have a problem once in a great while (actually, I've never had one Leupold fail and I have a LOT of them). Good luck.

T. O'Heir · January 16, 2020, 02:08 PM

"...41 grains of..." Two near max loads might be the issue. Not likely though.
You ever tried the thing with non-QD rings?
Don't think I'd be comparing an M1A with a Rock River AR-10 clone. Ain't the same thing. And it can still be the bedding, just a different kind. Lotta places for a AR-10 clone to move.
Grab the thing and wiggle(technical term) it to see if there's any movement between the upper and lower. Especially at the hinge. Do the same thing with the fore stock and the scope rail. Assuming said rail's screw are tight in the first place.

tank1949 · January 17, 2020, 07:50 AM

Thanks to all, but I have done all the above and will replace scope and rings. At first I thought inconsistencies with 168 Hornady match but then similar to 168 SMK!

Bart B. · January 17, 2020, 04:47 PM

Do you shoot other rifles MOA at most at 100 yards?

bfoosh006 · January 17, 2020, 05:28 PM

Sure sounds like a scope or mount issue.

Are you removing the scope and rings often ? ( IE actually using the QD levers. )

If so... make sure when you replace the QD mounts, that the "cross bar" / "index lug" is firmly against the muzzle end of the picatinney rail slot.

tank1949 · January 17, 2020, 07:35 PM

I have not removed ARMS/Leupold scope/rings and reattached. My M1A quick release Warne/Swarvoski combination loses about 1/2 MOA or less when removing and reattaching. It has a rock solid steel rail. I just had eye surgery so a range visit to test another scope is at least 3 weeks away. I'll lap ARMS and mount a Schmidt Bender on X-1. I know my Schmidt doesn't move (inside). If much better, I'll leave ARMS on and replace back with Leupold. Hopefully, I will not have to send Leupold back, AGAIN! THX

January 16, 2020, 10:16 AM	#1
tank1949 member Join Date: November 12, 2012 Posts: 243	ARMS or Leupold losing POI? I am having issues with my Leupold Mark 4 M1 or the ARMS quick release rings holding POI. A just installed them onto a new RR X-1, 308. I hand weigh charges, use only FC 308 hulls and CCI LR primers. Yet, my groups go from sub MOA to 3 MOA from 10 shot groups to 10 shot groups. I mainly shoot 41 grains of 8208 or 40 grains of AR Comp and 168 SMK bullets. If the RR was a bolt gun, I'd first suspect a bedding issue. A few years back Leupold replaced my Mark 4 with a new one after identifying internal spring problems causing similar issues. Now, the similar issues have returned. However, perhaps the ARMS quick release are not strong enough to maintain consistent MOA groups on a 308 and only suited for .223 rifle recoil. I have Warne quick release rings on my SA M1A that provide a rock solid mount system. No POI change!!! Has anyone has issues with ARMS quick release rings on 308s??? My next option is to change scopes and use Warne rings. However, unnecessary range visits are both expensive to my pocket book and to my shoulder. The shoulder is the worst!

January 16, 2020, 02:08 PM	#3
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...41 grains of..." Two near max loads might be the issue. Not likely though. You ever tried the thing with non-QD rings? Don't think I'd be comparing an M1A with a Rock River AR-10 clone. Ain't the same thing. And it can still be the bedding, just a different kind. Lotta places for a AR-10 clone to move. Grab the thing and wiggle(technical term) it to see if there's any movement between the upper and lower. Especially at the hinge. Do the same thing with the fore stock and the scope rail. Assuming said rail's screw are tight in the first place. __________________ Spelling and grammar count!

January 16, 2020, 10:25 AM	#2
NoSecondBest Senior Member Join Date: December 7, 2009 Location: Western New York Posts: 2,736	I own two of those scopes and one of my friends has a couple. Neither of us has ever had a problem. He's using one on a .338 Laupa and a couple of AR's. I'd try another scope and see what happens. That will quickly rule in/out if it's the scope. Even Leupolds can have a problem once in a great while (actually, I've never had one Leupold fail and I have a LOT of them). Good luck.

January 17, 2020, 07:50 AM	#4
tank1949 member Join Date: November 12, 2012 Posts: 243	Thanks to all, but I have done all the above and will replace scope and rings. At first I thought inconsistencies with 168 Hornady match but then similar to 168 SMK!

January 17, 2020, 04:47 PM	#5
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Do you shoot other rifles MOA at most at 100 yards?

January 17, 2020, 05:28 PM	#6
bfoosh006 Senior Member Join Date: February 17, 2009 Posts: 1,089	Sure sounds like a scope or mount issue. Are you removing the scope and rings often ? ( IE actually using the QD levers. ) If so... make sure when you replace the QD mounts, that the "cross bar" / "index lug" is firmly against the muzzle end of the picatinney rail slot.

January 17, 2020, 07:35 PM	#7
tank1949 member Join Date: November 12, 2012 Posts: 243	I have not removed ARMS/Leupold scope/rings and reattached. My M1A quick release Warne/Swarvoski combination loses about 1/2 MOA or less when removing and reattaching. It has a rock solid steel rail. I just had eye surgery so a range visit to test another scope is at least 3 weeks away. I'll lap ARMS and mount a Schmidt Bender on X-1. I know my Schmidt doesn't move (inside). If much better, I'll leave ARMS on and replace back with Leupold. Hopefully, I will not have to send Leupold back, AGAIN! THX