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Wake27
05-19-20, 11:48
I was grouping some uppers the other day and half way through I figured it wouldn’t be a bad time to do a basic RTZ test. Both uppers were previously zero’d with the optics on them. One was a BCM with Vortex Crossfire in Scalarworks mount and the other was a KAC Mod2 Carbine with a 1-6 Razor in the Badger C1 mount. The plan was to pull both optics, throw on my new 1-10 Razor (also in a C1), group with some different loads at 50 and 100, then return the original optics to their respective uppers.

First was the BCM. I didn’t plan on testing RTZ so I didn’t shoot an initial group, but it was zero’d at 50yds with the same ammo. After grouping and returning the Crossfire/Scalarworks optic, this is the group I shot to see if my zero shifted.

https://uploads.tapatalk-cdn.com/20200519/6582293bc501288d2abcfe7a08d46506.jpg

Next was the KAC. Same plan, but I shot an initial group this time. The horizontal stringing lead me to believe that I was doing something weird as the shooter, rather than the zero being a tad high vs the POA. I should’ve shot a second group but was running out of time.

https://uploads.tapatalk-cdn.com/20200519/d947360cf0e97de5943b032b74402b8e.jpg

Here is the confirmation group, and what I expected the initial group would look like.

https://uploads.tapatalk-cdn.com/20200519/83c08e4ffc4d9a60b4e8b3283f4869cd.jpg

Not overly scientific and small sample size, but I was pleasantly surprised at how well these two RTZ’d and figured I’d share here.

If anyone has experiences with some type of proof, I’m sure it’d help others to see.


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opngrnd
05-19-20, 12:34
This has me interested, even though I generally shoot Aimpoints. I'll try it next time I'm out.
gaijin
05-19-20, 12:41
No substantiation, but I’ve had a Scalarworks MRO amount off and on a 14.5 gun several times.
It has returned to zero.

My LaRue, ADM and Bobro (30mm) mounts all require a couple clicks of windage to be on.
Certainly useably accurate, but not “zero’d”.

It helps to provide forward pressure, push mount towards muzzle- to replicate recoil force, as you tighten mount to rail.
Wake27
05-19-20, 13:13
No substantiation, but I’ve had a Scalarworks MRO amount off and on a 14.5 gun several times.
It has returned to zero.

My LaRue, ADM and Bobro (30mm) mounts all require a couple clicks of windage to be on.
Certainly useably accurate, but not “zero’d”.

It helps to provide forward pressure, push mount towards muzzle- to replicate recoil force, as you tighten mount to rail.

Agreed, I use a paint pen to mark the rail slot and always push forward when tightening.


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1168
05-19-20, 15:47
I also push forward when tightening.

Yesterday I took a gun apart to install one of BRT’s gas restricting tubes. And I changed the suppressor mount due to erosion, and also loosened the barrel nut/rail because of URX4 ship-in-a-bottle issues. I made sure the URX4 was aligned perfectly again when I retorqued. I removed the Romeo 4T in LT660, and Vortex Micro 3x, to get them out of the way while I was doing this.

Today I went to the indoor range to test the function and at least the left-right zero. I was 1/2” left at 25yds. So, 2moa. Vertical component looked about right, but I’ll have to go to a real range this weekend to check. I think I got pretty lucky.

I can’t substantiate this.
gaijin
05-19-20, 16:37
^^Mirrors my experience; LPVOs lost “windage” zero by small degree. Elevation was ON with several examples.
Five_Point_Five_Six
05-19-20, 19:54
No substantiation, but I’ve had a Scalarworks MRO amount off and on a 14.5 gun several times.
It has returned to zero.

My LaRue, ADM and Bobro (30mm) mounts all require a couple clicks of windage to be on.
Certainly useably accurate, but not “zero’d”.

It helps to provide forward pressure, push mount towards muzzle- to replicate recoil force, as you tighten mount to rail.

This is exactly my experience with Scalarworks, LaRue, and ADM mounts for the micro red dots.
Straight Shooter
05-20-20, 07:01
Well, damn. Now Ive got another "test" to do next time at the range!
rushca01
05-20-20, 07:24
Interesting thread. I have scalarworks and LaRue mounts as my sample range. I’ll echo that I’ve never had an issue and even go one step farther in that once the optic is zeroed on one upper I can move it to a completely different upper (same caliber) and be about on with a few quick adjustments.