The MKMO – M = Maschinen, K = Karabiner M = Militär, O = Oben (Top ejection) – was designed for the military and to increase firepower it had a larger-capacity magazine as well as a longer barrel.Finland purchased approximately 282 of the original MKMO variant, which were used by the home guard, supply units and coastal defense forces in the Continuation War.[4] The SIG MKMO used a hesitation-locked operating system which kept the cartridge within the chamber long enough for the pressure within the barrel to decrease to a safe level.This system was adapted by Gotthard End based on a John Pedersen design first used in the Remington Model 51 pistol.This delay allows chamber pressure to drop to safe levels while the breech is locked and the cartridge slightly extracted.