Iron Sight and Low Power Scope Tracking Issue

[crossfire3006]

Hello, I have a curiosity question I'd like to ask and hopefully learn from or at least understand. This past weekend, I was helping a friend of mine put a brand new EOTech Vudu 1-6x24mm scope on his Winchester Model 70 375 H&H that he recently purchased. The scope has a 30mm tube and the rings and bases are Tally (rings are QD). We mounted the scope and verified twice it was mounted correctly. Here's where this issue started. When we looked through the scope at 1 power, the crosshair was not tracking to the front iron sight. It was about a 1/4' off to the right of the iron sight. We looked over the mount again and removed it, then mounted it again for a third time, assuring everything was done correctly. The same thing was happening, no change.

We decided to try something. We took my Winchester Model 70 375 H&H (manufactured in 1984) and mounted the scope on my rifle to see it the crosshair and iron sight would line up. Low and behold, it did the exact same thing. It was about 1/4" off to the right. Initially we thought either the the front iron sight was off from manufacturing or where it was drilled and tapped was off. Finally, we put the scope on another Winchester Model 70 with iron sights I have and the crosshair was just about right on with the iron sight.

What could be causing the issue with the 375 H&H being so far off, not only on his 375, but my 375 H&H as well. Has this ever happened to you? Is it most definitely something wrong with the scope? Thanks for reading my post and for any assistance you can provide.

​

 

[JimP]

It can all depend on the position of the front mounted iron sight.

As long as the scope holds on target who cares, it's two different sighting systems

 

[crossfire3006]

It can all depend on the position of the front mounted iron sight.

As long as the scope holds on target who cares, it's two different sighting systems

I understand, but it's more of an annoyance issue

 

[PARA45]

Is the scope and iron sights sighted in? Where is each hitting? That's where my focus would be. The 1 power will be used (maybe) during a charge, otherwise I wouldn't worry about it.

 

[mark-hunter]

I didnt catch if you tried shooting and zeroing both sights?

There is a window of moa adjustemts for windage on scope, which will eventually compensate for any iron sight misalligment.

I would do as follows.
Zero iron sights
Zero the scope.
If there is a problem remaining go to gunsmith.

 

[crossfire3006]

I didnt catch if you tried shooting and zeroing both sights?

There is a window of moa adjustemts for windage on scope, which will eventually compensate for any iron sight misalligment.

I would do as follows.
Zero iron sights
Zero the scope.
If there is a problem remaining go to gunsmith.

Thanks mark-hunter! His rifle is brand new, so he hadn't even fired a round through it. My 375 is zeroed in at the iron sight.

 

[Mark A Ouellette]

This is common.
If you press your cheek hard into the stock the crosshairs will APPEAR to move in relation to the metallic sights. Lessen the cheek pressure and the movement will reverse.

There may be a very small parallax issue when moving the eye via cheek pressure but most people will never be able to measure it by point of impact change with a dangerous game rifle.

When you move your eye a little side to side, if the crosshairs move in relation to the target, you have seen parallax. Parallax is usually set to be zero movement at a certain range of target.

 

[mark-hunter]

Eventually missaligned iron sigjts are not measure of barrels point of impact or aim. This is most important to understand.

Missaligments of drilled and tapped screw holes, can be fixed even by proper fixing of piccatinny rail on top.
(holes on the left, rail a bit to the right)

In any case, aftet checking zero for both sights, you will know if gunsmiths intervention is needed or not.

Trial at the ramge, first!

 

[baxterb]

My 9.3 had this issue and it was because the rear base holes were misaligned. I had custom bases made and fixed it.

Run a very small string over the front sight to the center of the rear base hole...are all four holes lined up?


And there is the matter of parallax as @Mark A Ouellette mentions.

 

[Nevada Mike]

I would have bore sighted the scope, then the iron sights. Then mount the bore sighted scope and shoot at 25 or 30 yards. Adjust scope to center of the bullseye. If the scope is "on" at short distance, try with the iron sights only. Adjust iron sights to center the bull.This will give you the whole story.

I have a M70 .375 H&H also. Never noticed the anomoly you posted about. Never looked, actually.