Glock 43X and 48 MOS Direct Fit Optics

Glock 43X & 48 MOS Optics: Everything You Need to Know

The Glock 43X MOS and 48 MOS are the gold standard for concealed carry, and their mounting system is slightly different from the full-sized Glock MOS models. Instead of using the MOS system of the 5th gen or interchangeable plates of the 6th gen, these "Slimline" models have a footprint milled directly into the slide that is based on the Shield RMSc footprint .

The "Direct Mount" vs. Adapter Plate Debate

The Glock 43X MOS footprint features four recoil bosses (nubs). While this allows some optics to sit directly on the slide, others require a small shim or adapter plate:

• Direct Mount Optics: Sights like the Shield RMSc , Osight SE , Sig Romeo-X Compact , and Vortex CCW are designed to fit these four bosses perfectly. These sit the lowest on the slide, often allowing for a full co-witness with standard-height factory sights.
• Holosun EPS Carry & SCS Carry: These are some of the most popular Glock 43X/48 MOS red dot options, but they only have two front recesses. To mount them, you must use a thin adapter plate to clear the rear bosses on the Glock slide, or have the bosses professionally filed down. This adapter plate is included in the box with these two optics.

Top Rated Glock Slimline Optics by Use Case

• Best Overall Carry Optic: The Holosun EPS Carry . As an enclosed emitter, it prevents dust and lint from blocking the laser-essential for a gun carried inside the waistband.
• Best Direct Fit (No Plate): The Vortex Defender-CCW . This mounts straight to the slide with no extra hardware and has a good co-witness.
• Best Value Optic: The Osight SE . It offers great battery life and has an enclosed emitter at a price point that is hard to beat for a Glock 43X optic .

Frequently Asked Questions (FAQ)

Does the Glock 43X MOS come with adapter plates? No. Unlike full sized Glocks, the 43X and 48 MOS do not include a plate kit. The slide is pre-cut for the RMSc footprint. If you want to run a different footprint (like the Holosun K-series), you must purchase an aftermarket plate.

What screws should I use for my Glock 43X red dot? This is critical: the screw on the right side (extractor side) must not be too long, or it will interfere with the extractor depressor plunger, causing malfunctions. Always use the screws provided with your adapter plate or specifically labeled for the Slimline MOS.

I have the Glock 43X MOS in Coyote (FDE), does this selection still apply? Yes, but with one major technical difference. The Coyote Glock 43X MOS features an updated "MOS-K" slide cut that removes the rear recoil lugs. This allows you to direct-mount optics like the Holosun 407K, 507K, and EPS Carry without an adapter plate.

Critical Note: While the footprint is improved, the screw holes on the Coyote model are threaded for M3 screws , unlike the M4 screws found on the standard black 43X/48 MOS. Using the wrong screw diameter can permanently damage the threads in your slide.