Height - 0.979" - 24mm base to bottom of ring equates to maximum scope outer objective diameter of 76mm - pretty much any large scope from 50-60mm+ lens size is fine.
 

• Tube diameter: 30mm
• Fits: 3/8" and 11mm dovetail grooves
• Overall Length: 4" - 101mm
• Clamp Length: 1.65" - 42mm
• Ring Width: 0.60" - 15mm
• Bottom of Mount to bottom of Scope Tube: 0.979" - 24mm
• Scope turret clearance: 0.125"
• Weight: 4.2 oz - 118

Calculating scope to rifle body clearance

The way you calculate the clearance is by halving the overall OUTSIDE diameter of your rifle scopes objective lens and then deducting half the rifle scopes body tube diameter.

For scopes with a 30mm diameter body tube this means deducting 15mm.

Note - OUTSIDE diameter - NOT the lens diameter, you need to measure the whole outer casing diameter.

The result gives you the minimum "saddle" dimension required - the measure from base of mount to bottom of the ring.

The amount the saddle dimension is greater than the figure you have calculated is the amount of clearance your scopes objective will be clear of your rifles body.  The saddle on these mounts is - 24mm - that is high

Example -

1. A scope has an outer case measurement of 64mm (AO scopes with 50mm lenses tend to be in this area of outer case size)
2. 64 divided by 2 = 32
3. 30mm scope so deduct 15mm from 32 = 17mm
4. So the mount must have a saddle measure (base of mount to bottom of the ring) greater than 17mm or else it will ground out on the rifle body.
5. So with 24mm there will be an easy 8mm clearance.

Calculating your rifle scopes clearance in this way does assume your dovetail or base is not raised above or below your rifles barrel. Note some rifles with high or adjustable cheek pieces may require higher scope mounts or risers so that your eye is in line with the rifle scope and your head is kept in an upright comfortable position.

What are the advantages of BKL mounting systems?
1 - Installation is performed easily because there are few components to contend with. BKL uses the same #8-32 screws for both scope ring and base clamps. One 9/64 hex wrench tightens all.
2 - The inside diameter where the rings clamp together is radiused to prevent scope damage.
3 - BKLs clamping system self aligns as it tightens down on 3/8” and 11mm dovetails.
4 - No lapping required.

Do I have to center BKL scope mounts?
No. All of our products center up as the pressure from the clamping system pulls down as it clamps in.

About BKL - Made in Texas, USA

BKL Technologies, manufacturer of the largest selection of airgun and rimfire scope mounts in the U.S. Our competition-grade scope mounting system includes scope mounts, scope rings, dovetail to weaver adapters, and scope risers that utilize a quick-installing and self-aligning clamping system that fits both 11mm and 3/8" dovetails.

BKL mounts are compatible with popular rimfire manufacturers such as Anschutz, CZ, Feinwerkbau, Marlin, Remington, Savage, Suhl and air rifle manufacturers such as Air Arms, AirForce, Beeman, Benjamin, BSA, Crosman, Daystate, Diana, Gamo and Webley.

See http://www.bkltech.com/ and ask us about any other BKL products you'd like to get