The batteries in my RMR went dead and you have to remove the RMR to replace the battery which I did. Now I am wondering if you have to re-zero or if it holds the zero? I looked around the internet and all I found was conflicting information.

Thanks
Ed

Yes you do.

It might be fine but I wouldn't count on it. Of the 2 times I took the RMR off my Sig P229, one time I didn't have to do anything, and the other time I had to make a slight adjustment.

You’ll probably have to re-zero. I do.

Thanks guys! I’ll get out to the range this week then.

How long did the rmr battery last ? I'm 18 months on mine.

Not sure as I got it used.

When I change my battery I always recheck the zero sometimes it is fine and sometimes just needs a slight change. I have never had a battery change result in a major change in the zero. I have let one battery go 18 months and it was still working fine but still like to change them yearly, just because it is a good idea.

You could get it “close” by alignment with the sights. But you will need to verify zero. If it’s a gun you carry for defense purposes and you use it - it’s always good to show you verified the red dot’s zero.

A lot is going to depend on how precise your cut is. I've moved RMRs between Agency Arms slides and not had to change the zero.

I would never remove one without verifying zero though.

In the future change it on a schedule before it dies, and do it on the range.

quote:

Originally posted by Mountain Man:
How long did the rmr battery last ? I'm 18 months on mine.

Mine lasted about 3 years. Always on auto adjust LED model.

I have a lots and lots of RMR's. So I've tested this a lot. The answer is it depends on the cut or mount, its mounting parameters and your installation methodology. In a closely fit/tabbed cut, with exactitude on (re)mounting (I 100% use a torque wrench for these after learning in the Type 1 flicker era)its pretty darn good. Good enough that in an emergency I'd change the battery and consider myself up and running for anything. But in a non emergency there is simply no reason to not check it. The worst I have seen it in dozens of remounts is that its fine for 'social' distance work, but you aren't going to nail 6" plates at 25y very well.