Choosing an APEL EAW scope mount involves more than finding scope rings with the same diameter as the riflescope tube. For a secure installation and a natural shooting position, the rifle, mounting bases, mounting system, riflescope, BH measurement and overall geometry must all be compatible.
This guide explains what BH means on APEL EAW mounts, how to interpret this measurement, the differences between the main EAW mounting systems and the information that should be checked before selecting a particular component.
Quick answer: BH comes from the German term Bauhöhe and refers to the construction or mounting height, expressed in millimetres. A larger BH raises the relevant component further, but there is no universal rule such as “BH10 fits every scope with a 42 mm objective”. Compatibility also depends on the EAW system, mounting base, rifle model, scope tube and actual outside diameter of the objective housing.
What Does BH Mean on an APEL EAW Mount?
In EAW technical documentation, BH stands for Bauhöhe, or construction height, expressed in millimetres. BH10 identifies a BH measurement of 10 mm, while BH17 identifies a measurement of 17 mm.
This value can be used to compare heights within the same component or mounting family. However, it does not automatically state the largest objective diameter that can be fitted. The measurement datum may differ between scope rings, front and rear feet, mounting bases, tops for rail-mounted scopes and complete mounts.
As a result, two components with the same BH can produce different final scope heights when fitted to different rifles, bases or mounting systems.
Guide to Interpreting BH Measurements
The following classification helps compare available BH measurements within the same APEL EAW product family. It does not replace checking the exact part number and technical drawing.
| BH measurement | Relative position | What must be checked |
|---|---|---|
| BH 3 to BH 8 | Very low within the corresponding product family. | Clearance above the barrel, action, iron sights and objective covers. |
| BH 9 to BH 12 | Low configuration. | Mounting-base geometry and outside diameter of the objective housing. |
| BH 12.5 to BH 16.5 | Intermediate configuration. | Overall height, shooting position, cheek weld and bolt clearance. |
| BH 17 to BH 20 | High within the corresponding family. | Cheek weld, eye relief and whether the additional height is genuinely required. |
| BH above 20 | Particularly high configuration. | Exact compatibility and ergonomics of the complete rifle and optic setup. |
Important: descriptions such as very low, low, intermediate and high are only comparative. They do not mean that a particular BH is automatically suitable for scopes with 42, 50 or 56 mm objectives.
Objective Lens, Objective Housing and Scope Tube: Three Different Measurements
One of the most common mistakes is confusing the nominal objective diameter with the outside diameter of the objective housing or the diameter of the riflescope tube.
- Nominal objective diameter: this normally appears in the scope designation, such as 3–12x56. In this example, 56 mm is the nominal optical diameter of the objective lens.
- Outside objective diameter: this includes the housing surrounding the objective lens and is normally larger than the nominal figure.
- Scope tube diameter: this must match the inside diameter of the scope rings exactly, for example 1 inch or 25.4 mm, 30 mm, 34 mm or 36 mm.
A scope described as 3–12x56 does not necessarily have an outside objective diameter of exactly 56 mm. The housing normally adds several millimetres. The actual dimension should be measured with callipers or taken from the riflescope manufacturer’s technical drawing.
How to Calculate the Minimum Scope Mounting Height
The following geometric formula can be used for an initial assessment:
Minimum scope centreline height above the base = outside objective radius − height difference between the base and barrel + safety clearance
Three measurements are required:
- Measure the outside diameter of the objective housing and divide it by two.
- Measure the vertical difference between the top of the mounting base or rail and the nearest point of the barrel, receiver or iron sights.
- Add a small safety clearance to prevent contact and allow for lens covers if required.
The result is the approximate minimum height required for the optical centreline above the reference surface. It is not automatically the BH of an EAW component. The technical drawing must be checked to determine the datum used for the stated BH and the total height produced by the complete setup.
Examples for 42, 50 and 56 mm Objectives
These examples demonstrate the calculation method. The outside diameters are illustrative; the actual riflescope must always be measured.
| Riflescope | Example outside diameter | Available height difference | Safety clearance | Approximate minimum centreline height |
|---|---|---|---|---|
| 42 mm objective | 48 mm: 24 mm radius | 8 mm | 2 mm | 24 − 8 + 2 = 18 mm |
| 50 mm objective | 57 mm: 28.5 mm radius | 8 mm | 2 mm | 28.5 − 8 + 2 = 22.5 mm |
| 56 mm objective | 63 mm: 31.5 mm radius | 8 mm | 2 mm | 31.5 − 8 + 2 = 25.5 mm |
These results should not be searched for directly as BH values in the product filter. First determine the required overall height. Then check which combination of mounting base, front and rear foot, scope ring or rail top provides that height on the particular rifle.
Quick Guide by Objective Size
| Configuration | Usual starting point | Essential check |
|---|---|---|
| 42 mm objective | Look for a low installation, provided there is sufficient clearance. | Outside objective diameter, iron sights and barrel profile. |
| 50 mm objective | An intermediate mounting height is often required. | Base height, lens covers and ocular position. |
| 56 mm objective | An intermediate or high configuration is commonly required. | Actual outside diameter and clearance above the barrel. |
| 34 or 36 mm scope tube | Rings of the exact diameter and suitable mounting height. | Do not confuse scope tube diameter with objective diameter. |
| Zeiss or Swarovski rail | A top section compatible with the integrated scope rail. | The exact rail interface and corresponding EAW part number. |
Which APEL EAW Mounting System Should You Choose?
APEL EAW manufactures different systems because not every rifle, optic and shooting application requires the same mounting solution. The selection should begin with the exact rifle and its available interface, rather than the riflescope brand alone.
EAW Pivot Mounts
The APEL EAW pivot mount is one of the manufacturer’s best-known solutions. It typically uses a pivoting front foot and a rear locking mechanism matched to the rifle. The system allows the riflescope to be removed and is designed to provide a high degree of repeatability when all components are correctly selected, installed and adjusted.
A pivot mount can be particularly useful when the riflescope needs to be removed for transport or maintenance, when the rifle’s iron sights are to remain usable or when a second compatible optic will be fitted.
Depending on the version, the system allows adjustment of the front and rear feet and compensation for certain manufacturing tolerances. Even with a repeatable mounting system, it is advisable to confirm zero after removing, refitting or changing an optic.
EAW Slide-On and Roll-Off Mounts
EAW slide-on and roll-off mounts provide another detachable solution for compatible rifles and mounting rails. Versions are available with scope rings, tops for rail-mounted riflescopes and configurations for Picatinny or Weaver rails.
Before selecting a slide-on or roll-off model, check the rail type, slot width and position, locking system and the upper interface used by the riflescope.
EAW Claw Mounts
Claw mounts are a traditional solution commonly found on classic European hunting rifles. Correct fitting requires specialist knowledge, particularly when mounting plates need to be fitted or adjusted to the firearm.
A claw mount should not be confused with a modern mount that is simply secured to a rail with screws. If a rifle already has a claw mounting system, its components must be identified and measured before replacing parts or fitting a second optic.
APEL EAW Blue Line
The EAW Blue Line includes mounting solutions for different hunting and sporting configurations. Depending on the model, the range includes roll-off, block and pivot mounts. Compatibility with other EAW components should only be assumed when it is stated for the exact part number.
EAW Black Line
The EAW Black Line is aimed at professional, sporting and long-range configurations. This range includes technical mounting solutions such as mounts with built-in inclination and systems intended for demanding optic setups.
Inclination, normally expressed in MOA or milliradians depending on the product, must not be confused with BH. BH describes a construction height, while inclination changes the angular relationship between the riflescope and the bore axis.
Additively Manufactured EAW Components
EAW also uses additive manufacturing processes for certain components and specialist solutions. Regardless of the manufacturing method, the exact part number, material, interface and intended application must be checked.
Scope Rings or Mounts for an Integrated Scope Rail?
Riflescopes are generally attached to a mount in one of two ways:
- Scope rings: the inside diameter of the rings must match the riflescope tube exactly, for example 1 inch, 30 mm, 34 mm or 36 mm.
- Integrated scope rail: the riflescope has a dedicated lower interface, such as a Zeiss rail, Swarovski SR rail, Schmidt & Bender Convex rail or another compatible system.
A 30 mm ring must not be used on a 1-inch scope tube, even though the difference may appear small. Integrated scope rails should not be assumed to be interchangeable either: each system has its own geometry and requires the corresponding mount.
Weaver and Picatinny: Similar but Not Identical
Weaver and Picatinny rails both use transverse slots and may look similar, but there are dimensional differences between them. Many accessories designed for Weaver can be fitted to certain Picatinny rails, while a Picatinny recoil lug may not fit correctly into a narrower Weaver slot.
Compatibility must be checked using the technical specifications of both the rail and the mount. Important factors include recoil-lug width, slot dimensions and position, and the available mounting length.
On rifles with substantial recoil, the recoil lug must bear correctly against the appropriate slot to prevent longitudinal movement.
How to Choose an APEL EAW Mount Step by Step
- Identify the rifle: manufacturer, model, version, action length and production year where relevant.
- Check the rifle interface: dedicated bases, Picatinny rail, Weaver rail, dovetail or another mounting system.
- Identify the riflescope: complete model, scope tube diameter or type of integrated scope rail.
- Measure the objective housing: use the actual outside diameter, not only the nominal objective size.
- Calculate the minimum height: consider the barrel, receiver, iron sights, lens covers and any additional accessories.
- Select the mounting system: pivot mount, slide-on or roll-off mount, fixed rings on a rail or a mount for an integrated scope rail.
- Check the part number: review the technical specifications and drawing for the exact EAW component.
- Assess the shooting position: the riflescope should sit as low as practical without compromising clearance, eye relief or cheek weld.
Practical Selection Examples
Stalking Rifle with a 3–12x50 Scope and 30 mm Tube
First measure the outside diameter of the objective housing. Then identify the rifle’s mounting base and calculate the required height. If the riflescope is to be removed for transport or maintenance, a compatible pivot or roll-off mount may be suitable. The scope rings must be exactly 30 mm.
High-Seat Rifle with a 2.5–15x56 Scope
A 56 mm objective commonly needs more clearance above the barrel than a 42 mm model, but the highest available BH should not be selected automatically. An unnecessarily high mount can worsen cheek weld and head position. The outside objective diameter, lens covers and rifle geometry must all be measured.
Riflescope with a Zeiss or Swarovski Rail
Scope rings are not selected by tube diameter for this type of optic. A top section compatible with the exact integrated rail is required. The resulting height, longitudinal position and necessary eye relief must also be checked.
Red Dot Sight for Driven Hunting
A red dot sight requires a base or adapter compatible with its particular mounting footprint. A low installation is normally preferred for a natural and rapid mount to the shoulder, provided it does not interfere with the receiver, bolt or iron sights.
Changing Between a Day Scope and a Second Optic
When two optics are to be used on the same rifle, each optic requires correctly matched and adjusted mounting components. Even when the mounting system is designed for repeatability, zero should be checked after each change.
Correct Torque for Mounting Bases and Scope Rings
Insufficiently tightened fasteners can move under recoil. Excessive torque can mark or deform the riflescope tube, affect its internal adjustment mechanisms or damage screws and threads.
Main rule: follow the specifications issued for the exact mount and riflescope. If the maximum torque stated by the two manufacturers differs, use the lower value.
There is no universal torque setting for every scope ring, mounting base and riflescope. The correct value depends on the screw size, material, thread, surface treatment, ring design and the load the riflescope tube is designed to withstand.
Good Installation Practice
- Always work on a completely unloaded rifle.
- Clean the contact surfaces and inspect them for burrs or debris.
- Use correctly fitting, undamaged tools.
- Place the riflescope in the rings without forcing the tube or correcting misalignment through screw pressure.
- Set eye relief from a realistic shooting position.
- Level the reticle before final tightening.
- Tighten fasteners progressively and evenly.
- Use a suitable torque driver when a value is specified.
- Do not add adhesives, packing materials or threadlockers unless expressly authorised.
- Check bolt operation and clearance around the entire riflescope.
- Zero the rifle and inspect the mount again afterwards.
If the installation requires fitting bases, adjusting pivot feet, correcting stress or carrying out work on the rifle’s receiver, it should be completed by a qualified gunsmith.
Common Problems and Possible Causes
| Problem | Possible cause | What to check |
|---|---|---|
| Objective housing touches the barrel | Insufficient mounting height or a larger-than-expected objective housing. | Outside objective diameter, BH, mounting base and available clearance. |
| Riflescope sits too high | The selected mounting configuration is unnecessarily high. | Whether a lower configuration can be used without contact. |
| Point of impact changes | Play, incorrect torque, poor contact or incompatible components. | Bases, screws, locking mechanisms, contact surfaces and zero. |
| Riflescope moves inside the rings | Incorrect ring diameter, contaminated surfaces or unsuitable torque. | Scope tube diameter, cleanliness and manufacturer specifications. |
| Adjustment turrets become unusually stiff | Possible stress or excessive pressure on the scope tube. | Ring alignment and applied torque. |
Components of an APEL EAW Mount
Depending on the system, an APEL EAW setup may include front and rear bases, front and rear feet, top sections, scope rings, levers, locking mechanisms, mounting rails, screws and adapters. Components that look similar are not necessarily interchangeable.
To identify the correct replacement component, it is advisable to provide the EAW part number, exact rifle model, riflescope, mounting system and dimensions of the existing parts. A generic description such as “EAW rear foot” is normally insufficient to confirm compatibility.
Frequently Asked Questions About APEL EAW Mounts and BH
What does BH mean on an APEL EAW mount?
BH comes from the German term Bauhöhe and refers to construction or mounting height. It is expressed in millimetres and describes the height of a component according to the relevant EAW technical reference.
Will BH10 fit a scope with a 42 mm objective?
This cannot be confirmed from those two details alone. You must also check the outside objective diameter, BH measurement datum, mounting base, rifle model and final centreline height.
Which BH do I need for a scope with a 56 mm objective?
A 56 mm objective commonly requires more clearance than a 42 mm model, but there is no universal BH. Measure the outside objective housing and the vertical difference between the mounting base and barrel, calculate the minimum centreline height and then check the appropriate EAW technical drawing.
Does the objective diameter determine the scope ring size?
No. The scope ring diameter must match the riflescope tube exactly, for example 1 inch, 30 mm, 34 mm or 36 mm. The outside objective diameter is used to determine the necessary mounting height.
Will a Weaver mount fit a Picatinny rail?
It may fit in many cases, but this should not be assumed. Check the recoil lug, cross-slot dimensions and the compatibility stated by the manufacturer.
What is the difference between a pivot mount and a roll-off mount?
A pivot mount is installed by engaging and rotating the front foot before locking the rear foot. A roll-off mount uses its own contact and locking system on compatible bases or rails. The correct choice depends on the rifle, optic and intended use.
Will an EAW pivot mount retain zero?
The system is designed to provide high repeatability when correctly installed and adjusted. Nevertheless, zero should be checked after removing, refitting or changing an optic.
What torque should be used on scope rings?
Use the specifications issued by the riflescope and mount manufacturers for the exact products. If the stated maximum values differ, use the lower figure. There is no single torque value suitable for every scope ring.
Should threadlocker be used?
Only if it is expressly permitted in the instructions for the particular component. The product and quantity must suit the thread and allow later removal. Threadlocker is not a substitute for correct fitting and tightening.
Can I install an APEL EAW mount myself?
Some rail-mounted systems can be installed by a suitably experienced user following the manufacturer’s instructions. Pivot mounts, claw mounts and systems requiring fitting, adjustment or work on the rifle should be installed by a qualified gunsmith.
What information is needed to identify a compatible mount?
You need the exact rifle model and version, its mounting interface, the complete riflescope model, scope tube diameter or integrated rail, outside objective diameter and intended use.
Find the Right APEL EAW Scope Mount
Explore APEL EAW pivot mounts, scope rings, mounting bases, front and rear feet, rails and components for different rifles and riflescopes.
If you have not yet selected a particular brand or mounting system, compare our complete range of scope mounts, mounting bases and scope rings.
For a broader explanation of mounting bases, scope rings, Weaver and Picatinny rails and mounting height, read our guide to choosing scope mounts, rings and rails.
