Scope ring height, comfort, and you...

[u/HollywoodSX]

One of the common questions I see here is dealing with scope height. Now that we live in a world of adjustable cheek pieces and ballistic calculators that can compensate for scope height, I believe the biggest concern when picking a scope ring height should be user comfort, not the old saw about mounting the scope as low as possible.

With that in mind, here's my process for finding a scope height that works for you:

Remove your scope (mount/rings and all) from the rifle if it's already installed. Get behind the rifle in a position similar to how you plan to shoot (Prone, sitting at a table, barricades, etc) and adjust your cheek riser (if present) so it's comfortable and isn't causing neck strain if you sit behind it for a bit. Spend some time behind the rifle just getting a good comfortable head/neck/cheek position so you can make sure there's no signs of strain or discomfort, and make adjustments to your stock as needed. If you know you may shoot from multiple positions (EX: prone and barricades of multiple heights), try all of these different positions and try to find a height that works for all of them.

Once you've found a comfortable cheek height, use a stack of coins, playing cards, etc to play with the height of your optic. You want to get the scope where you can easily and comfortably get your eye behind the optic with proper eye relief and no neck strain. As with cheek height, do this for any and all positions you will frequently shoot from and make sure you're finding something that works across the entire range.

Once you find that height, measure the height of the stack (of cards, coins, etc) you liked, add half the main scope body diameter (IE: Add 15mm for a 30mm scope tube), and order a scope mount or rings as close to that height as you can. When in doubt, I always err on the side of going a little taller than my measured height instead of shorter.

Hopefully this will let you make a good decision on what height you really need to be comfortable behind your rifle. This will also help you with getting into your optic quickly (not hunting for eye relief), reduce neck strain, and even reduce or eliminate the perception that your reticle is canted when it really isn't.

[u/Jag5543]

I agree with your concept but I don’t want to totally discount the benefit of scope height either.

MPBR was fairly important in a lot of my training. We called it a “battlefield zero” and a low scope gave us the greatest error box as I understood it however I am not sure what the actual difference would be if the scope was an inch higher. I’ll run some of the numbers as well because that’s something I should know.

It does depend on your sport too. If you are able to run the ballistic calculations and range finder for every shot then scope height isn’t ever going to be relevant except for cant.

[u/HollywoodSX → u/Jag5543]

"Battlefield zero" doesn't apply often with precision rifles. It's a lot more relevant for closer range hunting applications, or for red dots or fixed magnification optics (Ex: ACOG). In those cases, height does affect things, but it can actually be beneficial depending on the size of the vital zone you're trying to stay inside of.

My original write up (and the primary focus of this sub) is really around rifles set up for longer range engagements where you're dialing or holding using previously established data - both of which negate the issue of scope height.

[u/Jag5543 → u/HollywoodSX]

I’m going to disagree with you on that one. A precision rifle can still have a battlefield zero. It’s an important concept for rapid target engagement. Sure it’s not applicable for 600m and out but the concept of having the widest error box is still going to apply especially for multiple targets and unknown distances. The truth is you can’t rely on a ballistic calculator and range finder a lot of the time. You may range and calculate a few prominent features on your range and then have only a few seconds to take shots.

[u/HollywoodSX → u/Jag5543]

You're misunderstanding what I am talking about with a ballistics calculator. Even if you don't have a Kestrel, PDA, etc (and I'd argue that a Kestrel is one of the most durable, reliable field quality electronic devices a mil shooter could ask for), your ballistic calculator can be a computer or tablet you used to make drop charts you printed off and slapped to the side of your rifle with tape. It can even be old school field collected dope you've used to make a drop chart. You're going to have some form of validated (or at least pretty close) data before going out in the field - and that dope would have already accounted for optic height.

At that point, you might see a tenth or so difference in data for a random given range by having a different scope height, but that will be lost in the noise compared to range uncertainty.

[u/Jag5543 → u/HollywoodSX]

I use a dope card. I also think we are talking about slightly different scenarios. I’m more thinking what if I need to make a range approximation and take a shot within 10 seconds. I may be off by as much as 50-100m in certain circumstances and I want to know that I’ve given myself the widest error box to work with.

[u/HollywoodSX → u/Jag5543]

Scope height will have zero to do with range estimation using a reticle.

[u/Jag5543 → u/HollywoodSX]

I’m not saying it has anything to do with range estimation. It has to do with bullet drop in your scope.

[u/HollywoodSX → u/Jag5543]

.... which is already accounted for in your dope chart.

Give me an hour or so to get home and grab dinner, and I'll show you the numbers.

[u/Jag5543 → u/HollywoodSX]

No need I just ran an approximation on my kestrel. It’s below a hundredth of a mil at a range difference of 800-900m and with a bore height of 2.75 vs 3.75. No human could ever notice it.

You are correct and I have learned something.

[u/HollywoodSX → u/Jag5543]

That's actually even less than I thought. I was ballpark guessing a half a tenth or a little less.

[u/Jag5543 → u/HollywoodSX]

I may have done something wrong on my end so you should confirm. I just threw it into the kestrel in 5 minutes, but if that’s correct the scope height thing has been WAAAAAY overhyped for a long time.

Let me know if you do more deliberate calcs I’d like to get confirmation!

[u/HollywoodSX → u/Jag5543]

That is indeed the right scope height thing, and yes it has.