How to Pick Scope Ring Height Without Guessing

Low, medium, high: what do those even mean?

Ring makers sell "low," "medium," "high" and "extra high" rings, and those words mean different heights from one brand to the next. That is why so many people order rings twice. The fix is a little math with three measurements you can take at the kitchen table with calipers or a good ruler.

This guide walks through that math, the clearances you need to check beyond the objective bell, and how height fits with cheek weld. It is an editorial reference, not a substitute for your ring maker's own fit chart, which is always the final word.

Our mounting and zeroing guide covers ring height briefly. This piece is the detailed version.

What you need to measure

1. Objective bell outside diameter. The widest part of the front of the scope. On a 40mm scope the bell is wider than 40mm because of the housing. Measure it or find the maker's spec.
2. Main tube diameter. Usually 1 inch (25.4mm), 30mm or 34mm. Your rings must match exactly.
3. Base or rail height. The height of the top of the base or Picatinny rail above the barrel at the point where the bell sits. Measure from the top of the barrel (or barrel contour) under the bell to the top of the rail.
4. Ring height as listed. Ring makers usually list height as the distance from the bottom of the ring (or the top of the rail) to either the bottom of the scope tube or the center of the tube. Check which; the math changes.

The math, step by step

The goal: the bottom of the objective bell must clear the barrel (and anything else under it) with a small gap.

Step 1: Find how far the bell hangs below the tube

Bell drop = (bell outside diameter minus tube diameter) divided by 2.

Example: a bell measuring 50mm outside on a 30mm tube. (50 - 30) / 2 = 10mm of bell below the bottom of the tube.

Step 2: Find the height of the tube's bottom above the barrel

If the ring maker lists height to the bottom of the tube: tube bottom = rail height above barrel + ring height.

If they list height to the tube's centerline: tube bottom = rail height above barrel + ring centerline height - (tube diameter / 2).

Step 3: Check the clearance

Clearance = tube bottom height - bell drop.

If clearance is above zero, the bell clears the barrel. Most people want a small extra gap, a few millimeters, so a lens cap or a slightly bigger barrel contour does not touch.

Worked example

3mm of clearance is a workable fit. If the result had been 0 or negative, you would need the next height up. These numbers are illustrative only; use your own measurements.

Imperial works the same way. Just keep every number in the same unit.

Clearances people forget

• Bolt handle. On a bolt action, lift the bolt fully and cycle it with the scope mounted. The handle or your fingers should not hit the eyepiece or the power ring.
• Turrets and ring tops. The turret housing must sit between the rings without touching. Long turret housings limit how far you can slide the scope.
• Flip caps and sunshades. A flip-up objective cap or sunshade can be wider than the bell. Check that it opens without hitting the barrel or a front sight.
• Iron sights. A tall front sight post can hit the bell or block the bottom of the view.
• Ejection. On some actions the scope sits close to the ejection path. Make sure cases leave cleanly.
• Power ring throw levers. On LPVOs, a throw lever needs room to rotate.

Clearance is the minimum. Fit is the goal.

The math tells you the lowest rings that work. That is often the best choice, because a lower scope generally lets your cheek rest solidly on the stock and keeps the sight line closer to the bore. But it is not always right.

• Your face and stock decide. Shoulder the rifle with your eyes closed, then open them. If you have to push your cheek down hard or lift your head off the stock to see through the scope, the height is wrong for you.
• AR-pattern rifles have a straight-line stock with the comb well above the bore, so scopes sit much higher, usually in a one-piece cantilever mount. Our LPVO guide and mount height explainer cover AR heights.
• Cheek risers let you run taller rings on a classic stock without losing your cheek weld.
• Height over bore matters at short range. The higher the scope, the farther below the crosshair your bullet hits up close.

If you use the site's Zero Calc tool, note your scope's height above the bore. It is one of the inputs that affect where you hit at different distances.

Quick scenarios

Signs you went too low

• The bell or a lens cap touches the barrel.
• The bolt handle bumps the eyepiece.
• You have to crush your cheek into the stock to see a full picture.

Signs you went too high

• Your cheek floats above the stock, or only your jaw touches it.
• You see a dark ring around the image unless you lift your head.
• Close shots land well below the crosshair, more than you expected.

Choosing the rings

Match the base type

Picatinny and Weaver-style rails take many rings, though Picatinny slots are standardized and Weaver slots vary. Some rifles use proprietary systems: Ruger's integral bases and Tikka's dovetail are two examples. Buy rings made for your base.

Rings worth knowing

Ammunition Depot's scope rings category lists dozens of rings by height and tube size, including:

• Weaver Four-Hole Skeleton 30mm medium rings and their extra-high version for Picatinny rails.
• Weaver Grand Slam 1-inch medium rings for 1-inch hunting scopes.
• Ruger 30mm medium rings for rifles with Ruger integral bases.
• Tikka Optilock 30mm medium rings for Tikka T3 and T3x dovetails.

For an AR, look at one-piece cantilever mounts instead; Ammunition Depot's optics mounts category has them. Optics Planet's rifle scope rings section covers Leupold, Vortex, Warne and other makers if you want to compare more options.

Whatever you buy, check the maker's height spec and how it is measured, then run the math above.

Install tips

1. Clean ring and base screws of oil unless the maker says otherwise.
2. Install the bases or ring bottoms, torque to spec, and set the scope in loosely.
3. Set eye relief at the highest power in your shooting position.
4. Level the reticle to the rifle, then tighten ring caps evenly in a cross pattern, keeping the gaps on both sides equal.
5. Torque to the maker's values. Our torque guide explains why guessing is a bad idea.

Editorial note: This is an independent editorial reference built from manufacturer specifications, retailer listings and published sources. We have not performed hands-on testing of the products discussed, and nothing here is a performance promise. Verify specifications, compatibility and the law where you live.

Affiliate disclosure: Some links on this page are affiliate links to Ammunition Depot and Optics Planet. We may earn a commission if you buy through them, at no extra cost to you. Our editorial choices are not influenced by commissions. Check current price, stock and specifications directly with the retailer.