Glock 20 "Super Ten"

Glock Ges.m.b.H. introduced the Glock 20 in 1991. The manufacturer developed the firearm to address requirements within the law enforcement and security forces market for the 10mm Auto cartridge. The design followed the lineage of the Glock 17 but required a scale-up of the frame and slide to accommodate the increased pressures and dimensions of the 10mm ammunition.

The firearm utilizes a short-recoil, locked-breech operating system with a modified Browning cam-lock. The frame is constructed from a high-strength nylon-based polymer, while the slide is milled from a single block of ordnance-grade steel. Metal components receive a ferritic nitrocarburizing surface treatment to provide resistance to wear and corrosion. The internal mechanism features the "Safe Action" system, consisting of three independent safety mechanisms: a trigger safety, a firing pin safety, and a drop safety. These components prevent accidental discharge without the requirement for an external safety switch. Due to the specific dimensions of the 10mm cartridge, the major assemblies of this model are not interchangeable with smaller-framed Glock pistols. The hammer-forged barrel utilizes polygonal rifling to provide a gas seal behind the projectile.

The Glock 20 is utilized by various security agencies and specialized military units, including the Danish Sirius Dog Sled Patrol in Greenland. The manufacturer introduced a variant designated the 20SF, which features a short frame designed with a reduced trigger reach and a shortened heel for improved ergonomics. In 2013, the Fourth Generation model entered the commercial market, incorporating a dual recoil spring assembly to manage recoil and a modular backstrap system for grip adjustment. Other variants associated with this design include the subcompact Glock 29 and the long-slide Glock 40 competition model. In 2025, the manufacturer announced that production of certain variants would cease as part of a streamlining initiative, with future models designated to feature redesigned internal components.