Magazine Base Pad Extension for FNX 45

This magazine base pad extension for the FNX 45 adds 2.5 rounds of usable capacity to standard factory magazines. The half-round refers to the additional spring compression space that allows a fully loaded magazine to seat reliably with the slide in battery. It solves the common issue of needing to force or shave rounds to get a full magazine inserted on a closed slide.

Compatibility

• FN FNX 45 (all variants)
• FN FNX 45 Tactical
• Standard capacity factory FNX 45 magazines only
• Not compatible with 10-round or restricted capacity magazines

Key Features

• +2.5 round capacity increase over factory standard
• Maintains slide lock functionality on empty magazine
• Perimeter and front corner finger grooves for positive purchase during reloads
• Machined notches on bottom face for color marking to identify and track magazines
• Machined from 6061 aluminum with two finish options: Black Type III Hardcoat Anodized or FDE Cerakote (H-267 Magpul Flat Dark Earth)
• Single set screw retention for secure fit and easy disassembly
• Includes extra power magazine spring to ensure reliable slide lockback on empty
• Tool-free installation with provided hex key

Install Difficulty

1 out of 5. Requires a punch or small flathead to depress the magazine spring retainer. Hex key included. Install time under 5 minutes.

FAQ

Will this work with my FNX 45 Tactical?

Yes. This base pad is compatible with all standard capacity FNX 45 magazines. The Tactical model uses the same magazine body and spring system.

Why is it 2.5 rounds instead of 3?

The extension provides space for two additional rounds plus enough spring compression to seat a fully loaded magazine with the slide forward. Without this extra space, the spring stack would prevent the magazine from locking in on a closed slide.

Does this affect the last-round slide lock?

No. The included extra power spring maintains positive pressure on the follower to engage the slide stop after the final round is fired. The extension does not interfere with the factory slide lock mechanism.

Shipping & Warranty: Ships within 1 business day. This product carries a limited lifetime warranty against manufacturing defects. Not available for sale in California, Oregon, Rhode Island, or Washington. Check your local laws before ordering.