Rifle Scopes Which LaRue rings for Mk12 Mod 0?

hydro556

Gunny Sergeant
Full Member
Minuteman
Dec 1, 2007
2,742
5
53
STL, home of the Cardinals.
I am looking for a set of QD rings to mount a USO 1.8-10x37 TPal on my Mk12 Mod0 upper from PRI.

The "correct" rings are ARM's #22's. I am not buying anything else from ARM's and will use LaRue instead. It appears that the LaRue LT 123's are about the same height. I am just wondering if they will be too tall.

I just want the scope high enough for a good cheek weld and no higher. Can anyone say for sure if I need the the 123's to give the proper height or should I go with the lower LT rings?
 
Re: Which LaRue rings for Mk12 Mod 0?

What is the OD of the USO 1.8-10x37 Objective? Mic'd

The LaRue Tactical LT-123 are <span style="font-style: italic">"edit: corrected" 1.28"</span> from base to center line of main tube. The LaRue Tactical Ultra-Low Mount Rings QD LT-719 are 0.875", which is VERY Low on an AR platform. LT-719 are meant to be used with a base or riser.

I was able to clear a Leupold 4.5-14x40 with ARMS #22Low 30mm Rings 0.925" height on a PRI Recce Riser, but the flip caps on a full length rail, SPR Mod 0, will not clear. This combo height was 1.425" from receiver top, optimum for my mug.

Pics of what Im speaking of:
Nov09030Medium.jpg

Nov09035Medium.jpg
 
Re: Which LaRue rings for Mk12 Mod 0?

I am trying to determine what it is exactly. I was thinking it was relatively large for a 37mm objective, like most ERGO USO's, but since this is a TPal, it shouldnt be.

If anyone has the 37mm TPal, I would really appreciate a measurement. In the meantime, I will shoot Jeff a PM.

I am trying to decide between the LT 123's and the lower LT 719's (I think this is the correct model# for the lower ones)
 
Re: Which LaRue rings for Mk12 Mod 0?

I couldn't bring myself to use arms rings so I went with Badgers

Correct height is ARMS Med which are 1.150" . I went with Badger Highs 1.125" and it works perfect

CopyofMK12Mod0Noveske3.jpg


My 40mm objective Leupold just clears w/ caps

The Larue LT123 are 1.28" so you should be fine with those. The next lowest from Larue are too low for your application
 
Re: Which LaRue rings for Mk12 Mod 0?

I have both sets of Larue rings, the LT-123s and 719s. As SPDGG pointed out, the LT-719s are 7/8" high, which is quite low for use on an AR. The 123s are 1.28" high, but keep in mind that you should have a riser to use these as well. If you are definitely going with Larue, you need to go with the 123s. They are 0.405" higher than the 719s so you most likely won't be able to clear the rail, but equally important, you won't get a proper cheek weld. Here is my AR with the 123s, and the rifle has an arms SIR rail on it. With this setup, the bell of my 56mm scope is about 0.3" high off the front rail.

IMG_0019.jpg
 
Re: Which LaRue rings for Mk12 Mod 0?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hydro556</div><div class="ubbcode-body">Just bought a set of the LT 123's. Will try and remember to post pictures once everything is together.</div></div>

I think you will be super happy with those rings. They are a huge step up from the crappy arms #22s. I know because I replaced a pair of ridiculously tight, shifting zero #22s with a pair of 719s, compliments of Mark Larue on the trade in.
 
Re: Which LaRue rings for Mk12 Mod 0?

So using LaRue rings on an ARMS rail won't cause the universe to implode? I went to the ARMS rings due to the 1.15" height. I'd like to see how the LaRue 123's work on the ARMS rail. In retrospect, worrying about 1/10" height difference seems silly now that I think about it.
 
Re: Which LaRue rings for Mk12 Mod 0?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: skatz11</div><div class="ubbcode-body">So using LaRue rings on an ARMS rail won't cause the universe to implode? I went to the ARMS rings due to the 1.15" height. I'd like to see how the LaRue 123's work on the ARMS rail. In retrospect, worrying about 1/10" height difference seems silly now that I think about it. </div></div>

We shall see. I had both an LT-104 and a pair of FN rings on top of it and it shot fine. I scrapped the LT-104 bc the scope was way too high. I just hope the SIR doesn't give me any problems like those of the other arms crap I allocated over the years. It came as standard equipment on this rifle, so I am not too crazy about replacing it. One thing is for certain; if that SIR acts up on me, it is taking a trip to the trash (or on the WTS section on the 'hide).
 
Re: Which LaRue rings for Mk12 Mod 0?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: skatz11</div><div class="ubbcode-body">So using LaRue rings on an ARMS rail won't cause the universe to implode? I went to the ARMS rings due to the 1.15" height. I'd like to see how the LaRue 123's work on the ARMS rail. In retrospect, worrying about 1/10" height difference seems silly now that I think about it. </div></div>

They work very well. I cannot detect the very small height difference when shouldering the rifle.
 
Re: Which LaRue rings for Mk12 Mod 0?

With a 37mm objective, you should be fine no doubt. You said that your bell diameter is 1.85", and you are using a full length rail with no drop off, so:

1.28" - (1.85" x 0.5) = 0.355"

Hence, the bell of your scope will be 0.355" high off the rail. Don't second guess yourself about not going with the 719s, bc they would be too short by 0.05" and the bell would hit the rail. That rail is probably something close to 0.3" high off the receiver, giving you a bit more than the standard 1.5" height to centerline, so your cheek weld should be fine as well.
 
Re: Which LaRue rings for Mk12 Mod 0?

Got it mounted up. Turns out the LT 123's just barely didnt clear the ARM's 40 sight. I had to remove a tiny bit of material, basically the anodizing, LOL, from the sight. Fits perfectly now. Cheek weld is good, so I did not want to raise the USO.

Hope to start breaking it in this weekend.

mk12mod0005.jpg

mk12mod0004.jpg

mk12mod0006.jpg
 
Re: Which LaRue rings for Mk12 Mod 0?

Nice stick, Hydro--I have a bunch of parts just waiting to be put together into a Mark 12 Mod 0. I had to send my barrel back to have the collar step set back another .2 inches--was only getting a turn and a half on the suppressor. Then it is off to get the barrel cerekoted. So, I get to keep waiting...

Can you post an up-close picture of how much room you have on the bell of the USO? Reason I ask is because I am planning on using LT123's to mount my USO, but mine is a 44mm T-pal 3.2 x17 (which I am now going on 6 months waiting for from USO), hoping that I will will clear--
 
Re: Which LaRue rings for Mk12 Mod 0?

Got it to the range today in 20-30MPH winds blowing snow all over.

It was awesome!

A buddy of mine went with me with his new RECCE rifle, suppressed, with a NF 2.5-10. I love my MK12 Mod0, but that RECCE is badass. I may try and trade him out of it, LOL.

We zeroed both rifles pretty easily at 100 yards. Only had about 3 hours of daylight, and the wind chill was in the single digits, but it was simply a great time.

We were shooting a 45% IPSC steel swinger. Using the dope I had generated with my LaRue 20" SSS got us plenty close to be able to get 1st or 2nd round hits at 200 and 300. Then it became boringly easily with both rifles. Cant wait to work up a load for these rifles/carbines and build dope cards out to 650. Ammo used was Black Hills Match 68, 75 and 77 grain. Zero malfunctions with either rifle. Very impressed. Weather is supposed to be the same tomorrow and we are planning on getting out a bit earlier so we dont have to rush.

The USO performed great. Bright and clear and dialing up and down was consistent. Zeroing was easy. Overall great experience. This thing is going to be a shooter.

Pics in a bit,
 
Re: Which LaRue rings for Mk12 Mod 0?

Here are a few of my typically crappy shots. I really need an SLR.

My Mk12Mod0 with USO TPAl. LOVE the scope.

snowrangeSPRs001.jpg


Another of my Mk12, with my new Colt 6721 on the side. (The colt had several light primer strikes, disappointed. I am am going to disassemble, clean and lube the bolt. Hoping they greased it up too much or something. First AR I have had with this issue, and my first factory Colt, hmmm.)

snowrangeSPRs002.jpg


My buddies, BADASS Recce.

snowrangeSPRs003.jpg


The can is a 30 cal, but did a great job, was ear safe IMO. Shot well also.

snowrangeSPRs004.jpg
 
Re: Which LaRue rings for Mk12 Mod 0?

Went back today in howling winds blowing snow everywhere. Was absolutely beautiful. Too much wind to really gather much information, but we were not having too much trouble ringing the steel at 300 and 400 with all the rifles.

My oldest daughter was freezing (she took my coat, LOL) but she was probably the best shot of us all. Once zeroed, she had about 6-7 straight hits at 300 and was hitting at 400 at about a 75% clip. Awesome.

2009-12-27115048.jpg


we had the range to ourselves. This is what it looked like. The yellow of my buggy looks REALLY yellow.

2009-12-27100407.jpg
 
Re: Which LaRue rings for Mk12 Mod 0?

That is a fact SS, but (FWIW) the correct rear BUIS for the Mod0 is the ARMs 40, IIRC.

The issue has been resolved at this point. I have only had it to the range twice, and both times were in ~30mph winds and blowing snow(loved it! LOL), so I havent shot for groups, but ringing steel at 300 and 400 wasnt very difficult. Only a few rounds through it, but it seems like the Noveske SPR barrel is going to be an awesome shooter.

But, like so often happens with me, I am thinking about selling the Mk12, or at least the upper. Something else has caught my attention and as usual it is too much $$$ for me, so I may be listing an as new PRI Mk12Mod0 shortly, LOL.