DNZ scope mounts

[the blur]

I'm looking at DNZ game reaper mounts. They come in low, medium, high mounts. They are 1/8" difference in mounting height of the scope.

How much of a difference does it make (down range) if the scope is mounted 1/8" too high ?

My Zeiss scope does not fit in the medium mount, do to the underside of the scope hits the rail. And I could modify it, or get a taller mount. But I'd hate to mount the scope higher than necessary.......

 

[Kennibear]

By increasing the height of the scope over the bore center by 1/8" (0,125") a 300 WinMag with a 210 gr VLD doing 2950 drops 0.5" less at 500 yards (23.1" vs. 23.6")

Hope that helps.

Tipping the rifle off vertical causes more problems though.

KB

 

[the blur]

Effectively, your saying it's better to mount it higher ?

 

[whowa004]

Not better but it can be accounted for, most ballistic calculators (the one attached to this site does) has an option for how high your scope is mounted and then it will churn out the data you need to have an accurate drop chart! lower is better as it is more consistent over longer distances however with the larger objective lens sizes and main tube diameters the goal is to mount them as low as possible and then account for the difference in a calculator if it is different than the default value given.

Hope that makes sense and I didn't ramble on too bad

 

[Kennibear]

Up side is slightly less holdover @ long range.

Down side is the cant of the vertical alignment if you tip the rifle off level is exaggerated. That is, for the same cant the muzzle is off to one side or the other from vertical with the scope more. That throws the shot off to either side. If you must to use a high mount some sort of scope level becomes even more necessary.

KB

 

[the blur]

Please explain cant and hold over in English. User friendly terms. thx

 

[Kennibear]

Cant = rotation. When the scope is level the centerline is directly over the bore center. As you rotate/ tip/ cant the rifle either way the center of the scope moves to one side or the other of the bore/barrel center. The barrel is then not angling straight up but is also angling off to the side.

Hold over is how much you have to shoot over the target to hit where you want.

Welcome to Long Range Hunting!

KB

 

[the blur]

Are there any situations that "require" or prefer to have the scope mounted higher ? Or beyond a certain distance ? lightbulb

 

[Kennibear]

The only two I can think of are to clear a large objective lens at the front and to add clearance over the action if the rifle ejects the case into the scope. Early sniper scopes were on high mounts to clear the strait bolt handles on military rifles. Not a factor for modern guns.

Really low mounting can make it hard to get your head down behind the scope if the cheek of the rifle stock is too high. But it is better to get a proper fit on the stock than raise the rings.

KB

 

[7magcreedmoor]

If you haven't already done so, give the article "fitting the long range rifle" a good read. The issue of cheek weld is covered very well. How high your scope is mounted above bore is a factor which is more determined by the size of the objective bell and the contour of the barrel than anything else. We generally like to keep things as low as possible without those two parts touching each other, in order to avoid needing to raise the cheekpiece of the stock any higher than necessary to achieve clear sight picture. Sight height is a field in any good ballistic program because it is part of the geometry that must be calculated into the drop chart. The performance of the load doesn't change when you change scope height, but your viewpoint when taking the shot does. Play around with your ballistic program's sight height setting and compare drops at longer distances in the output to see what I mean. Kennibear's comments on cant are spot on: no matter how high or low you mount the scope, you need to keep the rig plumb or your shots will be thrown wide of the mark. I use a tool that rests on the barrel and the scope bell at the same time to install the scope plumb above bore, and install an anti-cant level at the same time. The eye and the inner ear can play tricks on you in the field, but a properly installed bubble level will not lie.

 

[FEENIX]

For what it is worth ...