MK12 ring question.

hippyshake

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Dec 1, 2011
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I just got my MK12 MOD0 upper from PRI and Im getting ready to order a vortex pst 2.5-10 MRAD, Im kind of wondering if leupold MK4 Low rings will be too low. What are your recomendations?
 
I have a mk12 mod 1 with a leupold mk4 3.5-10x40 attached via arms 22h rings. Gives me just enough room to clear my matech sight. Plus it's easy to remove optic and does maintain zero when you do.
 
With the added height of the top rail on a Mod 0, medium rings should clear most back up sights like the ARMS 40 or Matech. With a lower profile sight like a KAC 600 Micro or ARMS 40L, you might be able to get away with using low rings. I would try it first with a pair of cheap import rings to test fitup before putting a lot of money into rings that may not work.
 
With the added height of the top rail on a Mod 0, medium rings should clear most back up sights like the ARMS 40 or Matech. With a lower profile sight like a KAC 600 Micro or ARMS 40L, you might be able to get away with using low rings. I would try it first with a pair of cheap import rings to test fitup before putting a lot of money into rings that may not work.


I have the sight that came with it, I think its and arms 40 or 60.
 
The MK12 Mod0 was issued with ARMS #22 Medium Height Rings which are 1.150" high measured from the center of the optic to the base. The lowest Leupold MK4 rings likely to work are the Highs which are 1.06" high. Leupold medium rings are only 0.84" high. In this case "Medium" is just a name, the actual height is what you need.



Here are the original Mk12 Mod0 spec's:

Mod0
Barrel: 18-inch match-grade stainless heavy profile with 1:7 ratio, rifle-length gas system
Gas Manifold: PRI flip-up front sight
Muzzle Device: OPS Inc. 12th Model muzzle brake / collar to be paired with the 12th Model suppressor
Handguard: PRI Gen. III free-float
Sights: ARMS #40 rear flip-up, PRI front flip-up
Optics: Leupold LR M3 3.5–10×40mm, 2.5–9×36mm TS-30, or 3–9×36mm TS-30 A2; Leupold Mark IV MR/T 3–9×36mm in civilian market
Buttstock: Operator-specific but A1, A2, and LMT SOPMODs are common
Mounts: ARMS #38 SWAN Sleeve rail mount, ARMS #22M scope rings, ARMS #32 bi-pod mount (Harris) or ARMS #42 (Versa-Pod)
Bi-pod: Harris or Versa-Pod

Lots of pictures of Mk12 Mod 0/1 here: http://www.mk12.net/MAIN.html
 
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OP: It makes a difference depending on what Viper PST you are getting. There are two different objective piece differences with the 2.5-10x PST's.

The earlier models have a 44mm objective.

The newest FFP models have a 32mm objective.

That could play a role in what ring height you need. The Leupold MR/T scopes commonly used on the SPR's have a 36mm OBJ.

Since the Mod 0 used the SPR-specific ARMS Swan Sleeve, there could be a clearance issue if the rings are too low with the x44mm Viper PST.
 
Hippyshake , if you look at a lot of pictures of MK12 Mod0's posted you will see those trying to run as close to a clone as possible, running the correct Leupold with ARMS 22M. However the scope is pushed forward to clear the rather tall ARMS 40 rear sight. I run a NXS 2.5-10x24 on mine, the 22M wouldn't work with the standard ARMS 40, plus I didn't want to push the scope out further so I changed the rear buis to a 40l. You can see theres still plenty of clearance for a larger objective.
 
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Sorry for the delay, dang long day at work. This is my mk12 mod1 with leupold mk4 3.5-10x40 arms 22h rings. Never lost zero with multiple detachments of optic. Clears matech rear nicely.
 
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I just got my MK12 MOD0 upper from PRI and Im getting ready to order a vortex pst 2.5-10 MRAD, Im kind of wondering if leupold MK4 Low rings will be too low. What are your recomendations?
Arms # 22 Med Rings with 2.5x8 TS 30
I put my MK 12 Mod 0 together in 2010 after I returned from Iraq. Douglas Barrel and all I did put a sharps bolt in it and Roller Cam .....man it shoots sweet with IMR 8208 and 77 Matchkings, its my favorite AR by Far!
 
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