Trouble staying zeroed.

[tcecil88]

I bought a Glock 40 MOS 10mm with a Vortex Viper MRD to deer hunt with and as a year round woods gun. This is my first and only 10mm, so far. I replaced the OEM sights with Trijicon suppressor night sights. This appears to give me lower 1/3rd co-witness. I am having trouble zeroing the red dot after over 700 rounds. It does not seem to hold zero. I am thinking of removing the sight altogether and installing a set of adjustable sights and calling it good, but I don't want to give up on the red dot. I have a couple questions for the people with more experience with the MRDs.
If the iron sights and the MRD are sighted in for the same range (for now) wouldn't the front sight and red dot be stacked on top of each other or overlapping? Mine are off from left to right, which drives me crazy. (OCD I guess)
I would like to have the irons sighted for say, 15-25 yards, depending on how well I can shoot the pistol, and the red dot zeroed for longer range shots like 25-50, depending on the drop of the bullet. I am using Underwood 200 grain XTP at 1250fps and the Glock will be braced over a rest when deer hunting. Is this a realistic goal, or am I just wasting ammo trying for this?
Lastly, am I just overthinking this whole deal? I realize that they are separate sighting systems but I feel like they should work together.
Thanks for any advice.

 

[cedartop]

That is not an uncommon problem with the Vortex unit. I gave up on them after my second one. (Replacement from Vortex)

I have never heard of anyone zeroing their dot and sights for different distances, but then again I am more into using it for self defense and gaming, not hunting.

 

[42769vette]

Yes in theory if the red dot, and irons are sighted in for the same range, the red dot would be your pumpkin on the post. Sighting them in for different ranges would not be impossible, but I will say Ive never tried it in real life.

Did you loctite the base when you did your mounting?

 

[tcecil88]

I was wondering if the slide reciprocating speed from the 10mm was too much for the Viper. I thought thought about just moving it over to my G41 MOS .45 thinking it might do better on it. I am pretty new to the pistol red dot game and have not had much luck so far.

 

[tcecil88]

Yes in theory if the red dot, and irons are sighted in for the same range, the red dot would be your pumpkin on the post. Sighting them in for different ranges would not be impossible, but I will say Ive never tried it in real life.

Did you loctite the base when you did your mounting?

If you are referring to the MOS plate, no, I did not. I have checked the plate screws and they seem tight, but I will Loctite them for added security.

 

[42769vette]

If you are referring to the MOS plate, no, I did not. I have checked the plate screws and they seem tight, but I will Loctite them for added security.

Loctite should always be applied to the base. That may be your issue, it may not. Make sure you use med strength not high strength.

Did you torque the screws down with a torque wrench, or did you just tighten them to "that should do it" during mounting?

 

[Vigilant]

Trijicon RMR, the only serious MRDS for handgun use there is. Although the Leupy Delta Point Pro appears to be proving just as rugged!

 

[natdscott]

Lastly, am I just overthinking this whole deal.

Way.

Have you fired the pistol on targets every 5 yards over your desired range? Most CF pistols are fairly flat inside 50 yards. Some, such as your near-magnum, are VERY flat...for some targets they can be viable at 100 yards, just by holding over a little.

In my estimation, you need to do some paperwork and recording on the range and you'll quickly see that a 25 yard zero with the irons is WAY usable at 50 yards. I'd be very impressed if your Glock (or most other pistols) could even shoot the difference between a 25 and a 50 yard zero.

Were it me, I'd zero BOTH sights at 50 yards, and be very happy with the knowledge that I am basically POA = POI to over 75 yards and I have a very usable dusk sighting system, while still being fully functional in bright sun or if the batteries die.

Hell of an idea what you're thinking of, but you're not trying to split playing cards here.

-Nate

 

[tcecil88]

Loctite should always be applied to the base. That may be your issue, it may not. Make sure you use med strength not high strength.

Did you torque the screws down with a torque wrench, or did you just tighten them to "that should do it" during mounting?

The Viper was already installed on the pistol when I bought it. I have checked the mount plate screws and they have loctite on them. Glock does not specify a torque, so I torqued them to 25 in-lbs. I also torqued to Viper's mount screws to 25 in-lbs. I will retry the zero tomorrow. Thanks for the replies.

 

[tcecil88]

Trijicon RMR, the only serious MRDS for handgun use there is. Although the Leupy Delta Point Pro appears to be proving just as rugged!

Yeah, I missed out on the Cabela's sale on the Trijicon RM01. They were cheap for awhile. One of these days.....

 

[42769vette]

The Viper was already installed on the pistol when I bought it. I have checked the mount plate screws and they have loctite on them. Glock does not specify a torque, so I torqued them to 25 in-lbs. I also torqued to Viper's mount screws to 25 in-lbs. I will retry the zero tomorrow. Thanks for the replies.

That may very well be your issue (May not as well). Most folks just tighten down to "about there". Something like 40% of issues on optics are due to improper mounting industry wide.

 

[tcecil88]

Way.

Have you fired the pistol on targets every 5 yards over your desired range? Most CF pistols are fairly flat inside 50 yards. Some, such as your near-magnum, are VERY flat...for some targets they can be viable at 100 yards, just by holding over a little.

In my estimation, you need to do some paperwork and recording on the range and you'll quickly see that a 25 yard zero with the irons is WAY usable at 50 yards. I'd be very impressed if your Glock (or most other pistols) could even shoot the difference between a 25 and a 50 yard zero.

Were it me, I'd zero BOTH sights at 50 yards, and be very happy with the knowledge that I am basically POA = POI to over 75 yards and I have a very usable dusk sighting system, while still being fully functional in bright sun or if the batteries die.

Hell of an idea what you're thinking of, but you're not trying to split playing cards here.

-Nate

The indoor range I go to I can check POI at 5 yard intervals out to 50 yards. I will try that. Like I said, I don't have alot of experience with MRDS, so any help is much appreciated. This has been very frustrating for me. I have alot of money wrapped up in this pistol and all the ammo I have shot through it, so the sooner I get it zeroed, the better. I may ditch the tall sights, and just concentrate on the Viper.

 

[tcecil88]

I got to the range today with the G40. At 15 yards with the iron sights, it shoots the Underwood 200 gr. XTP into 3 inches, 1 inch high, off a bipod. Good enough for a deer. Moving onto the red dot. At 25 yards, it shoots into 3 inches centered in the bull, after adjustments. I shot it at 50 yards and my group opened up to about 9 inches, but it was a vertical string that was centered on the target. Good enough for a deer. I was able to raise my head a little and center up the dot in the scope's window, which let me put accurate shots on target. I concentrated on the target and let the dot be fuzzy, then moved the dot on target, which seemed to work ok.
As I have said before, I don't have alot of experience with pistol mounted red dots, but it seems I have the Vortex sighted in now. I am going tomorrow and see if it holds the zero, and if it does, I will call it good.