Removeable Scope Mount Repeatability

[ucrt]

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I have an ADM T-1 1/3 Cowitness Mount. A few weeks ago, at 50-yds., I shot 5 shots removed the T-1, tapped it on the wooden bench, remounted, fired five more shots, removed/tapped/remounted fired 5 more shots, removed/remounted/tapped 5 more shots. I had fired 20 total shots with 3 remove/remount/taps. My 20-shot group measured 1.75".

I don't know what the consensus is on a 1.75" group with a T-1 at 50-yds but I was tickled with it. In my experience with a T-1, I think the ADM is very repeatable.

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[IrishDevil]

I've had good success with my Larue mounts repeating within .5" or so at 100 yards. I bought an ADM mount for my M4S and it had some initial problems with repeating at 50 yards, it would go to the left or right about 1-1.5", I adjusted it to be as tight as possible and the issue went away. It now repeats so close I can't tell a difference. The latch is now so tight it takes a bit of muscle to get it locked. I've seen this with ADM mounts belonging to others, and it's been eliminated with the same tight as hell adjustment. I've never seen or heard of one shifting that much though. While I do like the design of the ADM mounts, I'm not too crazy about having to adjust it so tight. Also, the uppers I'm using are BCM, Sabre, Noveske, and CMT.

[shootist~]

Thanks for the comments. I am going to remove the mount and try a position a few slots forward to see if the results change.

I would be surprised if it did not change the POI if moving to different slots on the upper. That's asking too much.

I've had my Larue SPR mount off a couple of time with no noticeable change - scope is a NSX 2.5-10x32. I even dropped the upper (not on purpose) and banged the hell out of the bell on my bench - then removed the mount and still no change in POI.

ETA: No movement on my ADM/Aimpoint setup either and it's been off a number of times. Just as IrishDevil pointed out, the ADM is on tight - I have to use my Larue bottle opener as a breaker bar to open the ADM throw lever (works great, too).

[opmike]

I bought an ADM mount for my M4S and it had some initial problems with repeating at 50 yards, it would go to the left or right about 1-1.5", I adjusted it to be as tight as possible and the issue went away. It now repeats so close I can't tell a difference. The latch is now so tight it takes a bit of muscle to get it locked. I've seen this with ADM mounts belonging to others, and it's been eliminated with the same tight as hell adjustment. I've never seen or heard of one shifting that much though. While I do like the design of the ADM mounts, I'm not too crazy about having to adjust it so tight. Also, the uppers I'm using are BCM, Sabre, Noveske, and CMT.

I've experienced a similar issue with one of my ADM mounts on my BCM upper, and I wish they would use something other than the hex design. 1/6 increments for the tension are simply too large. 1/8 or 1/10 would be better.

[Singlestack Wonder]

[QUOTE=shootist~;704947]I would be surprised if it did not change the POI if moving to different slots on the upper. That's asking too much.
QUOTE]

You misunderstood. The problem occurs using the same slots. I'm going to move the mount forward a couple of slots, re-zero, and then remove and remount to see if the issue remains.

[ccoker]

agree on getting it "tight" but be warned that you can snap those cross bolts.. wonder how I know ?

I gotta give the Wilson a plug here, at first, I really didn't like the looks of their twist knob, but, it flat out works and is consistent.
You can get it very, very tight
And you can do it with gloves on even. I really, really like the setup

[ALCOAR]

I have fielded two recon x's extensively for a cpl. yrs. and recently have been trying the scout x's....and I have never lost repeatablity or a single zero one time with the 3 ADM glass mounts I own plus a ADB2 w. socom riser. So I would for sure say that if you have any loss at all you should see about getting that particular mount looked at.

[ALCOAR]

I would be surprised if it did not change the POI if moving to different slots on the upper. That's asking too much.

I've had my Larue SPR mount off a couple of time with no noticeable change - scope is a NSX 2.5-10x32. I even dropped the upper (not on purpose) and banged the hell out of the bell on my bench - then removed the mount and still no change in POI.

ETA: No movement on my ADM/Aimpoint setup either and it's been off a number of times. Just as IrishDevil pointed out, the ADM is on tight - I have to use my Larue bottle opener as a breaker bar to open the ADM throw lever (works great, too).

I have a lil trick I use that just involves some thin parachute rigging cord.....I just cinch a loop up at the tip of each lever and use the cord to get the needed leverage to pop the latches.

[shootist~]

I have a lil trick I use that just involves some thin parachute rigging cord.....I just cinch a loop up at the tip of each lever and use the cord to get the needed leverage to pop the latches.

Sounds like a good solution.

The LaRue Tactical Entry Tool hooks onto the ADM mount perfectly and makes releasing the throw lever easy as popping the top on a frosty. It came as a freebie with my LT-104, btw and now stays in my AR range bag.

[ucrt]

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My T1/ADM has been very repeatable but I agree that 1/6 turn steps are too large. If I go a 1/6 tighter, it is way too tight.

So, I took a 7/32" ID Buna O-Ring and put under the hex-head slotted nut. This o-ring is 1/16" thick and will raise the hex-head slotted nut just above and out of the hex hole that keeps the nut from turning, so you have to be careful that the flats of the hex-head slotted nut are lined up with the flats of the hole before you tighten the lever. If you don't line them up, you might mess up the mount (or the nut)??

Once you tighten the lever, the hex-head slotted nut is pulled into the hex hole. With the o-ring being 1/16" thick, you can feel a little bit of springiness in the lever but not too much. Heck, I see how much better the o-ring improved the AR extractor, figured it couldn't hurt here.

Next week, when I shoot, I'll try my "shoot, unmount, remount, shoot" routine again and see how the mount repeats but I think it will be fine maybe even better.

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