A thread on here last week about the repeatability of Larue removable scope mounts prompted me to do some testing.  Let me preface this with the admission that I am just a guy that has a passion for the best of the best when it comes to all things firearm related. For me, the most important factor in all firearms, is accuracy and precision, regardless of what it costs.  There are many high priced weapon platforms, scopes...etc. that I have bought and sold or do not use because they don't fit my needs accuracy and precision wise.  That does not make these products bad, everyone has their expectations and use for a product, for my use and needs these did not prove themselves to be what I want. Let me also say I am by no means a formally instructed , white coat wearing, lab product vetting type of any sort. Point is I am sure that there are better ways to test these mounts but this is how I did it and in my mind it seems to have been a feasibly relevant test. On to the good stuff.

As some here that may have seen in previous posts of mine, I have what is IMO, an extraordinarily accurate 18" OBR.  A rifle that shots far better than 1/2 MOA, 1/4 MOA is closer to the average, every time it spits a projectile out. The perfect platform to test any optic, mount etc.  If this rifle does not shoot it is the fault of something other than the rifle itself.

Test Rifle:

Larue 2012 yr model 18" OBR

Nightforce NXS 5.5-22x56 scope.

TBA Supressor

Handloaded Ammunition 175g Berger OTM

Mount Tested:

Laure LT112 PSR20,  this is the 20 MOA mount.  





This rifle has had somewhere around 1000 rounds shot out of it.  The only scope it has ever worn is this nightforce scope.  This LT112 mount has been on the rifle for roughly 500 of those rounds.  I changed to the 20 MOA LT112 to get more distance out of the scope.  1300 yards was max using the full adjustment range and the reticle with the previous LT111.  The LT112 got me to 95 MOA of adjustment which gets me wayyyy out there.

 In the past when I have seen comments criticizing Larue mounts there is talk of "slide marks" on the underside of the mount, where it has slid back and forth under recoil. I will agree that this is a highly likely scenario with a mount that is NOT adjusted properly.  In the next picture you will see that this mount with over 500 rounds, has no sign of slide marks.  In fact you will see the oil dots where the rail contacts the mount and they are pristine where they ride the rail.  This photo was taken after firing the first 3 shots as the test control target.  





I have also seen comments criticizing Larue mounts that if the mount was tight enough to keep from sliding then the levers would tear up the rail.  I do not remove the scope from this rifle very often, maybe it has been off 10-15 times over the period of 500 rounds.  After I was done shooting this test and had removed and re mounted the scope 8 times, I took this photo of the rail.  There is no damage or distortion to the rail.  There are several spots where the Anodizing has been marred, which IMO is a non issue and not what I would call damage.



Now the meat.  It has been well documented here with load development in this rifle how well it will shoot.  I shot a 3 round control group to compare the next two targets to.  I know there are people here that require 76 round groups to agree anything is proven, give me a pass here, a 5 round test group would have just made the final results boring, trust me.  For the test I had a single target with 6 aiming points, I only used the top row of 3.  The first group on the left, is the control group.  For the next group I removed the scope, took pictures of the underside of the LT112 (posted above) Fired one round, removed scope, fired another, removed scope and fired another, for a 3 round group.  The next target I did the same, starting by removing the scope and re mounting and then shot a 5 shot group with the same remove/shoot procedure.  



1. control group size:  .264

2. 3 shot group size:  .341  (Removed/mounted every shot)

3. 5 shot group size   .344  (Removed/mounted every shot)

In my opinion I would say this is a fairly revealing test.  With these results it is hard to dispute that the Larue mount, when properly adjusted, will return to zero in an amazingly consistent manner.  Going in to this I had assumed that the results would be great but I honestly did not think it would be this consistent.  I figured if there was less then 1/2 MOA movement then I was happy and the test was a success.  If this rifle still shot MOA with a 5 shot remove/mount group I thought that would be excellent results.  I am sure these results are no news to the folks at Larue, Mark and Mark are likely saying, "told you sumbitches".......  I am a fan of Larue products because they work, they are quality engineered and executed and last but not least they reside in the greatest country known to man......................TEXAS





Hosted photos to save OP's bandwidth -mfingar

I suppose that settles it.....

in

Great Write up OP.  Thanks for sharing.

Well, that's that!

Good shooting. The RTZ of the scope mount is amazing. Going to end up getting one, as it's certainly "more accurate" than the rifle it will go on. Thanks!

Don't take this the wrong way, but TOS is responsible for moving a lot of $400 Sphur mounts. Not that they aren't great mounts, but I would imagine they are a bit on the overkill side for most hunters and shooting enthusiasts. Especially in light of all the above.

OP, are you saving the predatobr take down results for another thread?  Good stuff, for sure....

Yes I will do my best to get it up here in the next few days.  

Thanks OP.  Seems pretty obvious at this point how it went

But you missed the bullseye...

somebody was gonna say it.

no fair OP, you had to present facts with your argument...

What you got against chain jerker's anyway?  

You ain't fooling nobody OP, I see your 5-shot group got blown over by a whoppin'  .004" bigger than the 3-shot group ...

This is a true observation.....and I will say it is either completely the mounts fault or some frog hair got wedged in there. Either way I can live with it.    



 

Okay, enough of this, standing by for your tOBR report.

The reason I hate 3rd groups, is you can take a shitty barrel and get a few lucky 3 round groups, with shitty ammo. But rarely does that ever occur with a 5 rounder.

Also OP, please shoot the 1 MOA all day challenge. LaRue desperately needs some entries in there, my tOBR is probably another year out.

I have never had a doubt about my LaRue mounts but it is always nice to see real human results. For the record I have a set on a .338LM that likes to wreck cheap mounts and scopes. It will not even budge the LaRue's.

Thanks OP for taking the time and presenting your experiment so well. Excellent presentation!

Good shoot op

It's nice to remove the optic when cleaning....etc....and know it's gonna hold zero



It's a wonderful thing

Yawn...  This was shot after installing and removing the scope on my 18" OBR all season (on/off each trip out) while hunting four legged critters.  I'm using a Storm 3200 case with Larue cut foam so scope removal is required (not that it's a problem).

Not necessarily my best shooting, but the critters didn't know the difference.

Safetyoff, my hat is off to you, very nice work. I always am drawn into your threads, no BS here.

I luv threads with a happy ending...  

Independent testing has proven that LT kit, is best kit

Excellent.

Roger that,  much appreciated comment and interest......my friend the red dot sniper!

What was the distance you did your test at OP?

100 yards was the test distance.

 

That's why I tell everyone I know who is looking for a scope mount to go with Larue.

If your going to test a Larue mount at least test it with a little more recoil like I did
I realy don't plan to ever remove the scope and mount from the gun BUT if I ever need to I wanted to know what to expect.
I did the same kind of test but at 100 and 200 yards and had the scope on and off about 10 times between test just to see if I could
loose my zero.
The damn thing held its zero

Is it over already? Man I missed another one.





Good shooting OP

I'm thinking safetyoff's tOBR homework assignment is about due!

Back before the whole do LT mounts hold zero question was such a big topic I use to transport my OBR in the case they come with. I always took the scope off and put it on when I got to the range. Never had a problem.
I now have a different case so it stays on now, but I have no concern about taking it off if need be.  

Great thread OP

Had to travel for business, it's coming for sure fri or sat when I get back to my computer.

 

Well, it's Friday.....don't see it yet.


Maybe you clicked the wrong button?

Something to hold you over until I can get my post together..... Impatient bastages

 






 

ETA - I need better glasses - can't see nuttin'.

We built something years ago that allowed us to see a 1/16 moa to 3/32 moa shift ... close enough for horseshoes.

A military organization used "their" gazzillion dollar lasers that shot to the moon and back - and came to the conclusion it was no more than .085 moa shift.

Those .mil folks would not let us have their official results due to their thinking it would give us an unfair competitive advantage achieved through the use of taxpayer dollars.

So be it, it is what it is.

No it won't, cause Haters got to Hate.............

The more they hate, the more I'm gonna make 'em hate.

O that's just not fair.

 

I don't know, but my  SPR/M4-EER mount with my Nikon P – 223 that I use pretty much just for working up new loads, has come on and off 2 different ARs of mine. I zeroed it to one of my AR's that I like to shoot more than the other one, and just remembered the windage and elevation clicks I needed to mount it on the other AR.

As long as I mount it the exact same way every time pushing it all the way forward, pressing down tight, and locking the levers in the same order every time. This mount has returned right to 0.

So all the haters can put that in their pipe and smoke it.