Pennsylvania State Police SERT Selects Geissele MK1MOD0

Geissele Automatics announced in an Instagram post that the Pennsylvania State Police Special Emergency Response Team (SERT) has adopted the MK1MOD0 Mid-Range Gas Gun. The announcement was light on other details like how many rifles the contract was for, or when they will be delivered. But we can glean some information from the pictures in the social media post.

Geissele @ TFB:

• Geissele Announces 12.5” and 13.9” Super Duty Variants
• US SOCOM Selects Geissele Automatics for MRGG-S
• Geissele's Border Patrol Rifles Coming To Civilian Market
• [SHOT 2024] Geissele Automatics Displays New AK Trigger And El Corto SBR Some
• Geissele Super Duty Rifles Win LAPD SWAT Contract

US SOCOM adopted Geissele’s submission for the Mid-Range Gas Gun-Sniper (MRGG-S) contract in 2023 and called it the MK1MOD0. The Geissele MRGG-S rifle has a 20-inch barrel and wears a Super Night Owl Double Wall suppressor, also made by Geissele. It has a “Desert Dirt Color” finish and ambidextrous controls.

The MK1MOD0 adopted by Pennsylvania SERT has an obviously shorter barrel than the MRGG-S rifles. Based on the length of the Geissele suppressor (6.89 inches), the barrel on this gun is likely around 14.5 inches long. Another difference from the SOCOM setup is the stock. This gun swaps out the MRGG-S Magpul PRS Lite for a B5 Collapsible Precision Stock.

The optics package deserves some attention as well. A Schmidt & Bender 3-20x50 PM II Ultra Short in FDE is the primary optic. Somewhat unsurprisingly, that scope sits in a Gesissele Super Precision mount. An Aimpoint Acro red dot finishes off the optics setup, mounted on top of the front ring.

Geissele also published a picture of the MK1MOD0 in a deployment case, and another picture shows a B&T Atlas bipod mounted with a Really Right Stuff adapter. Magpul PMAG LR/SR 20 in Medium Coyote Tan are pictured in the rifle, and it has a SERT logo on the right side of the magazine well.

If other prior Geissele contract guns (like their Border Patrol rifles) are any indication, we will probably see a version of this gun for the civilian market at some point. That is not yet confirmed, but keep an eye on our SHOT Show 2025 coverage in January to see if we can get a closer look at this gun.