The Glock 31 is a full-size pistol chambered in .357 SIG, dimensionally matching the G17 and G22. The .357 SIG cartridge offers a flat trajectory and high velocity in a straight-walled case that feeds reliably, and the MOS variant supports direct optics mounting.
Upgrades for the Glock 31
The Glock 31 can be tailored across the main competition upgrade areas:
Grips – panel texture and frame profile change how consistently your hand returns to the gun, the foundation of recoil control and a repeatable draw.
Triggers – a refined trigger sharpens the break and shortens the reset, so shots break where you expect and you are back on the sights sooner.
Sights and red dot mounts – upgraded irons or a slide-mounted optic give a single focal plane and faster acquisition from the holster and between targets.
Magwells – a wider, chamfered magazine well makes the reload more forgiving under stage pressure.
Base pads – extended pads add capacity and a little weight at the base of the magazine, and help it seat reliably.
Frame mounts and weights – added forward weight settles the muzzle and improves balance, particularly in Open setups.
Magazine releases and thumb rests – an extended release speeds mag changes without breaking your grip, and a thumb rest gives a fixed hand reference.
Compatibility is specific to each model — confirm the fit on the individual product page before ordering.