Welcome to the official user manual for the CZ 457 PRO Scope Base by Position7. Machined from 7075 aluminum with a hard-anodized finish, this premium one-piece 30 MOA scope rail solves real-world rimfire problems to give you ultimate reliability and flexibility.
1. Installing the Scope Base
Safety First: Always ensure your firearm is unloaded and the chamber is completely clear before beginning any installation.
- Thoroughly clean the factory dovetail on your CZ 457 receiver to remove any factory grease, oil, or debris.
- Do not install the deflector until the scope base is attached to the action dovetail
- Slide the one-piece clamping system of the PRO Scope Base directly onto the factory dovetail from the rear to front.
- Position the base so throwing window perfectly aligns.
- Torque Specification: Gradually tighten the 4 clamping screws in an alternating cross-pattern to ensure even clamping pressure. The maximum torque for these screws is 5 Nm (approximately 44 Inch pounds). Do not over-tighten!
2. The Brass Deflector: Function and Purpose
If you’ve spent enough time behind a CZ 457, you have likely seen it happen: occasionally, a spent case ejects straight up instead of out to the side. Often, this “rogue brass” bounces off standard scope bases and falls right back into the action, blocking the next round and forcing a time-consuming magazine change on the clock.
Our PRO Scope Base features a unique brass deflector. Its purpose is simple but critical: it catches and redirects those high-flying cases safely away from your action, ensuring your rifle runs smoothly without unexpected jams.
3. Installation of the Deflector
Note: The cutout in the CZ 457 action is not symmetrical front to back. Ensure you are using the correct version (Left-Handed or Right-Handed) that matches your rifle.
- Identify the correct orientation for the deflector based on your rifle’s ejection port.
- Carefully align the deflector component with the designated cutout/slot on the scope base.
- Seat the deflector fully so that it sits flush and secure, ensuring it is aligned. There should be an even gap from the action all around the deflector.
- Tighten the screws to about 1-1.5 Nm. Optionally put little of blue Loctite on deflector screws.
5. Mounting Optics: “Wet” Installation Recommended
To achieve the most secure and consistent interface between your scope rings or mount and the CZ 457 PRO Scope Base, we highly recommend using a “wet” mounting technique.
What is a “wet mount”? “Wet mounting” (or “wet scoping”) involves applying a very light layer of grease or heavy oil directly to the bottom of the scope mount or the contact surfaces of the Picatinny rail before clamping them together.
Why do it? When clamping bare metal to bare metal, friction can bind the components and prevent them from aligning perfectly. By introducing a light lubricant to these mating surfaces, you significantly reduce friction during installation. This allows the mount to slide into its natural center and seat perfectly square against the base as you apply torque. Ultimately, this creates a stress-free, rock-solid optical interface that helps prevent zero shift under heavy recoil or field use. It also ensures repeatability, when removing and and remounting your scope rings.
For further assistance, technical specs, or questions regarding your CZ 457 PRO Scope Base, please contact the Position7 support team.