preface:
In 2014 i purchased a BRAND NEW Aimpoint Micro H1 from larue tactical, with their LT660 (high) mount. I am shooting PMC .223 (brand new)


question: I have an aimpoint micro h1 on Larue LT660 mount and i go to the range with the rifle, every 3-4 months or so, and the 50 yard "ZERO" is almost always off by about 2 inches, in any other direction (up, left, right).

i am using the standard Mil-Spec 25meter zero sheet(pictured below), and i always have to adjust the sight by at least 1-2 inches in any one direction. i leave the range with the POI in the inner center circle. i come back in a few months and the POI is off by 1-2" inches. WHATS GOING ON?? is my red dot broken?

How are you storing the gun?
Is everything tight?

That's why I like iron sights.
Rugged, no batteries, etc.

gun is in a large soft case. its treated very well 24/7.
even if it was a little bumped around while in the trunk, we are talking about a combat sight, not some cheapo $50 walmart special.

i do know ambient temps play a role in trajectory, and i understand cold/hot barrel... but 1-2" EVERY SINGLE TIME is starting to confuse me a little.

Just a guess, but 1. you have a scope mounted on a high mount, and 2. you shoot every 3 to 4 months.

Having a high mount may be causing you to adjust your cheek to stock weld, which will affect how you view your sight picture. With a red dot, it shouldn't make any difference because where the dot is, should also be where the shot goes. Is your rifle set up to co-witness with iron sights? The irons would give you a stable reference to determine if the red dot is drifting. Shooting every 3 to 4 months reduces consistency in how you hold the weapon and how you see the sight picture. Do you set the dot on the same intensity every time? Turning up the intensity also tends to make the dot seem larger.

Not saying you're doing anything wrong, just saying there are some things to look at. Good Luck.

__________________
SFC, US Army, Retired

aimpoint mico h1 is not a scope. its a 4moa red dot.

and when i check the zero, i put the red dot on the lowest setting my eyes can see at. its beyond faint. i do this to reduce the size of the dot.

and no it does not co-witness. i have fold-down troy indst iron sights.

Forgive me, your OPTIC is mounted on a high mount. Even on low, a 4MOA dot alone will account for a 1 1/2" to 2" difference at 50 yards, since 4MOA equals approximately 4 inches at 100 yards. Red dots are in a sense, combat optics designed for quick target acquisition, not precision shots. If everything is tight and you feel there's a problem, contact Aimpoint. They'd be more than happy to take care of you.

__________________
SFC, US Army, Retired

Do you remove the Red Dot between shooting sessions? If so that is the most likely cause for the sight "drifting". Yeah, I know, QD mounts are supposed to repeat. In my experience the only mounts that repeat are the slide on mounts IF they are tightened with a Torque Limiting screwdriver. AND they'll only repeat if you aren't too critical about accuracy at 200 yards or more.

The second possibility is a poor cheek weld. The simple fact is a good cheek weld is critical for accuracy no matter what you are shooting with.

The Aimpoint sights are parallax free. That means that cheek weld plays no part in shot placement. Nor does where the red dot appears in the lens.

Having said that, one of the first things that comes to mind is loose bolts/screws between riser and optic. IIRC, the Aimpoint H series has the mount built into the body. Also, check the tension between riser and rifle.

The other item that might be in play is the 3-4 month layoff between shooting sessions. I don't know what your experience level is, but changes in how you place your hand on the grip and pull the trigger can cause the issues you mention. In other words, it's a software problem.

Added edit: I don't know what size dot you may have in your H1. What we expect from red dots is that the bullet will be somewhere in that dot at reasonable ranges. Might be at the top of the dot, might be at the bottom.

Secondly, unless you have no other option, quit screwing around at 50 yards. Zero your rifle at 50 yards/meters and confirm the zero by firing at longer ranges. Frankly, if you're off 2 inches at 50yards, the problem is most likely you, not the sight.

If your hitting anywhere within 3 inches of your poa at 50 yards with a red dot, you don't have anything to worry about.

Seems like your OCD about it.

Get a scope of you want to be dead nuts at 50 yards.

Are you shooting 10 round groups every time? If you're not, you're probably chasing your own tail and your zero isn't actually moving.

The Trouble With 3-Shot Groups - AR15.COM

H1 is rated 4moa dot. It's actually about 3.5.

As long as the shooter is holding center on target the size of the dot really isn't that big of a deal.

Make sure optic is properly secured to the mount. Push forward while flipping the QD lever to tighten on rifle.

Sounds like you are shooting from a rest with dot dialed down to the lowest setting thinking that's a way to get small groups on paper. Forget about it. Stand up, hold the rifle like it was meant to, crank up the dot to whatever point you can easily and quickly pick up the dot, and shoot the rifle. That's what the red dot is for. With a little practice you should see a consistent grouping on paper.

I have an H1. The last time it was on paper was when I zeroed it new. After that I've been shooting steel off hand. As long as I hear a clank at 60, 100 and 200 I really don't care if it's hitting a bit high, low, left or right. Maybe I might check it on paper. It's been a few thousand rounds.

You've got a real nice optic. Enjoy it.

i always try and do a "zero" test with the first mag while at the range. this gives me a good indication if the optic is functioning fine, and if anything is wrong with the rifle (lose barrel nut, etc).
i am a little OCD about having a perfect zero, and i think you guys are right about that.

i will check the mount screws that secure the optic.

regarding the qd knob: i made sure to make it tight prior to installing it the first day.

thanks for all your responses, and keep them coming; i really appreciate them

I do LE training for Aimpoint, so I deal with this stuff often. First it is not likely that the optic is the issue. For some red dot systems based on how they are powered and adjusted, zero shifts are common. That is not an Aimpoint issue. First,where is the sight mounted in your rail. If it is anywhere other than entirely on the receiver, I can just about guarantee that is the problem. How tight is the LaRue mount to the receiver. There are video's on their sight and YouTube from LaRue on how to properly adjust them. I have seen many cases where they are too loose. Ensure all the boots in the bottom of the sight are tight.....do not crank them down as you have steel in aluminum. I suggest loctite, to snug. Again don't kill them just ensure they are snug.

The size of the dot is irrelevant. It is actually a 3.4. I have shot plenty of sub 1 inch groups at a 100 yards with 2 MOA dots, and I have a pretty bad astigmatism, so they are more like an asterisk. The key is a consistent hold. Also, look through the dot and not at the dot. That is a very common issue.

As other have suggested, if you have some kind of back up iron sight system, the dot should be sitting centered on the tip of the post of the front sight when you are looking through the irons. This is how I confirm that both the irons and red dot are zeroed.

Hope this helps.