PS90 Chop Tops with Different Sight Options

Published on July 25, 2025
Duration: 2:34

This video details the 'chop top' modification for the FN PS90 and P90 platforms by MK3 Firearms. The process involves removing the factory sight structure and machining a custom Picatinny rail directly into the receiver, creating an inset mount. This modification aims to provide a sleeker profile and, crucially, an optimal height for a proper cheek weld when mounting optics, addressing previous issues with mounts being too low.

Quick Summary

The 'chop top' modification for the PS90/P90 involves machining a custom Picatinny rail directly into the receiver. This creates an inset mount with an optimized height for a proper cheek weld, offering a sleeker profile and improved ergonomics for optic mounting.

Frequently Asked Questions

What is the 'chop top' modification for a PS90 or P90?

The 'chop top' modification involves removing the original sighting structure from the top of the PS90/P90 receiver and machining a custom Picatinny rail into it. This creates a sleeker profile and, crucially, an optimized height for mounting optics.

Why is the new rail height important for PS90/P90 modifications?

The new, higher rail height achieved with the inset Picatinny rail in version two modifications is critical for allowing a proper cheek weld. This ensures consistent sight alignment and improves shooting accuracy compared to lower mounts.

What are the benefits of machining the Picatinny rail directly into the PS90/P90 receiver?

Machining the rail inset into the receiver creates a more robust and integrated mounting solution. It also allows for a higher rise, which is essential for achieving an optimal cheek weld and a better shooting experience.

What types of optics can be mounted on a PS90/P90 with a chop top modification?

Various red dot sights are compatible with the custom Picatinny rail. Examples shown include the Acro, RMR, and SRO optics, which are popular choices for modern firearms.

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