scope not tracking? Am I going crazy?

[EXPRESS]

Today I was out shooting and hoping to pen in the range marks on my turret with my new 6.5-284.
It was not a great day to shoot, starting out cloudy, then turning grey, gusty and finally raining.

My shooting position was good solid and confortable, prone on my mat off the Harris, with the legs in the dirt. And I was also shooting well today, I mean, I only pulled one shot of the 30 I fired.

Here is how he session went;

Started at 100, was zeroed at 165, moved estimated 8 clicks and shot went .5" from point of aim.
Went back to 200, entered elevation clicks, fired one shot, height spot on, 1.5" right. There was a 3-5mph crosswind, so ok.

Went to my 300 target, fired a group, found no holes. Was shooting close to edge of target board. Gave it 5 clicks (1/8th clicks) for wind and shot at target in middle of board. Height was right, but 4" right. Realized I'd put windage in wrong way. Doh!. Ok.

Moved on to 400 target, it's gusting 5 -12mph now, hit 2" high 8" left. Put in half MOA down, 3moa wind, try again, still same height, too much windage. Corrected windage.
Aimed at my 500 target, 4" high, still having trouble getting windage right but at this stage I'm concerned with getting the drops.

By now I was starting to give up on the idea of getting the job done, so I decided to just keep shooting. I wouldn't normally be this sloppy but I had to burn up the ammo remaining to get it all on the same number of firing/reloadings.

Shot some groups at the 400 and 500 targets, one measured .4moa, but by now it was truly dark grey with light rain falling, only 11am. The anemometer gave a pressure altitude of 50 feet higher than when I started, but pressure still the same?? Temp had dropped from 70° to 57°.
Raining and frustrated now, so I decided to put in a group at 300. Group was 3.5" off and 5" high, but I had penned in the 300 mark on the tape I'd put on the turret at the begining of the session.

Does the fact that I end up with a confirmed zero being nearly 2 MOA different to the original setting indicate that the scope is not repeating it's ajustments?
It is a Nikon Monarch Titanium 6.5-20x44, a halfway decent optic, not one I would expect to come apart like this.

So what was it, the scope, the crazy weather/light conditions, a combination or what, have any of you ever had a range session like this one?

I've order the Leupold I've been eyeing off for the last few months, so I will get a proper scope on it soon enough, but maybe wednesday I want to go back out and shoot the same marks again to see if it wasn't the weather or my head playing tricks with the numbers or something...

 

[WildRose]

Today I was out shooting and hoping to pen in the range marks on my turret with my new 6.5-284.
It was not a great day to shoot, starting out cloudy, then turning grey, gusty and finally raining.

My shooting position was good solid and confortable, prone on my mat off the Harris, with the legs in the dirt. And I was also shooting well today, I mean, I only pulled one shot of the 30 I fired.

Here is how he session went;

Started at 100, was zeroed at 165, moved estimated 8 clicks and shot went .5" from point of aim.
Went back to 200, entered elevation clicks, fired one shot, height spot on, 1.5" right. There was a 3-5mph crosswind, so ok.

Went to my 300 target, fired a group, found no holes. Was shooting close to edge of target board. Gave it 5 clicks (1/8th clicks) for wind and shot at target in middle of board. Height was right, but 4" right. Realized I'd put windage in wrong way. Doh!. Ok.

Moved on to 400 target, it's gusting 5 -12mph now, hit 2" high 8" left. Put in half MOA down, 3moa wind, try again, still same height, too much windage. Corrected windage.
Aimed at my 500 target, 4" high, still having trouble getting windage right but at this stage I'm concerned with getting the drops.

By now I was starting to give up on the idea of getting the job done, so I decided to just keep shooting. I wouldn't normally be this sloppy but I had to burn up the ammo remaining to get it all on the same number of firing/reloadings.

Shot some groups at the 400 and 500 targets, one measured .4moa, but by now it was truly dark grey with light rain falling, only 11am. The anemometer gave a pressure altitude of 50 feet higher than when I started, but pressure still the same?? Temp had dropped from 70° to 57°.
Raining and frustrated now, so I decided to put in a group at 300. Group was 3.5" off and 5" high, but I had penned in the 300 mark on the tape I'd put on the turret at the begining of the session.

Does the fact that I end up with a confirmed zero being nearly 2 MOA different to the original setting indicate that the scope is not repeating it's ajustments?
It is a Nikon Monarch Titanium 6.5-20x44, a halfway decent optic, not one I would expect to come apart like this.

So what was it, the scope, the crazy weather/light conditions, a combination or what, have any of you ever had a range session like this one?

I've order the Leupold I've been eyeing off for the last few months, so I will get a proper scope on it soon enough, but maybe wednesday I want to go back out and shoot the same marks again to see if it wasn't the weather or my head playing tricks with the numbers or something...

Before jumping in too deep let me suggest this.

Tomorrow go out and fire one cold bore shot at 200yds and see if your zero is still the same.

My guess is you have a free float/bedding issue rather than a scope issue and that will go a long ways towards diagnosing the problem.

If your first cold bore shot is not dead on where you ended up today, odds are it's the rifle rather than the scope.

 

[RDM416]

+1 for what Wildrose advised.

At the ranges you were shooting the changing weather conditions should not have mattered to the degree you are describing, for the rifle anyway. Nasty weather and quickly changing conditions can have an effect on the shooter too....... not saying that is the problem, just try it another day when the conditions are stable before you get too wound up.

A simple 5 round "box" test for your scope will help diagnose any repeatability issues with your scope. Make sure you let the barrel cool completely between shots to make sure you are not having poi changes due to barrel heating or bedding.

 

[EXPRESS]

Guys that's the best path to take. I doubt it is a bedding issue because the rifle shoot great groups, and it wasn't getting too hot between shot - I was running back and forth to the targets on my quad bike to check impacts because I couldn't see them through the spotting scope due to the poor light.

I will see what happens.

 

[Greyfox]

I have had bad days like this and I turned out to me and the next session went great. Who knows why? On the other hand I have had a couple of scopes over the years that I suspected of having tracking issues and it did turn out to be the case. In both cases the tracking issue did show up when I got back home and did a box test with a collimator . The one that I use came from Cabelas , is very well made with a series if matched caliber quides, and has a 4 MOA grid for reference that covers a wide adjustment range. At the right magnification, a solid rest, and good lighting observing .25 click movements are very evident and repeatable with a good scope. Also, when the scope comes back from repair, you can determine if it was fixed properly. After I had my first tracking problem I started doing this test when I mount a new scope. It may not be ultra precise, but this test could possibly save a lot of time, ammo, and frustration.

 

[EXPRESS]

Why didn't I think of that myself? I have both a laser bore sighter and an old Tasco grid style one.
It just never occurred to me that I could use them to test that the reticle is tracking properly.

Also...with the grid style, I could permamently fix a level to it (with the whoel thing actually level) and use it to gt my scopes mounted level to the bore too!

Thanks for the inspiration!

 

[WildRose]

Why didn't I think of that myself? I have both a laser bore sighter and an old Tasco grid style one.
It just never occurred to me that I could use them to test that the reticle is tracking properly.

Also...with the grid style, I could permamently fix a level to it (with the whoel thing actually level) and use it to gt my scopes mounted level to the bore too!

Thanks for the inspiration!

It's a good way to look for basic mechanical issues but if something has busted loose that moves on the shot it won't show you that.

 

[EXPRESS]

So it turned out that this scope, an older Nikon 6-20x42 actually takes 6 clicks to move POI 1MOA, instead of the 8 clicks stated on the turret...