In 1915 the German Rifle Testing Commission at Spandau decided to develop a new weapon for Trench fighting. Originally intending to modify an existing weapon, technical issues made this impractical so the Commission determined that a completely new kind of weapon was needed. Hugo Schmeisser eventually designed a weapon to fulfill the requirements. This weapon was designated Maschinenpistole 18.I (MP18). The MP18 was a solid weapon, for it was a soundly engineered piece of equipment with near commercial grade fittings. The MP18 had a well machined walnut butt stock and breech block, and the blow back mechanism was made of the finest materials. Produced by Bergmann, it served in the later part of the war. It was used by the German police force after the end of the war.
The MP28.II was an improved version of the MP18, used by the German police and by SS units. A version of this weapon was made in Switzerland known as the SIG M1920, and one by Steyr Solothurn in Austria known as the MP34.
Operation
The original MP18 was designed to use the Snail drum magazine that was designed for use in the long barreled Luger Artillery model pistol. This rotary design type of magazine holds 32 rounds of 9mm ammunition and the user would have to load the magazine with a separate, and unique loading tool. As the snail drum magazine was originally designed for the Luger pistol, a special sleeve was required when the Snail drum was used on the MP18. This sleeve was slipped over the top part of the magazine and was used to stop the Snail drum from being inserted too far into the receiver and jam the firearm when it was fired. Later modifications to the MP18 allowed the use of a staggered box type magazine as used in the later developed MP40 sub-machine gun. The MP18 could only fire in the fully automatic mode, while the later developed MP28.II was designed to allow the user to select single shot or fully automatic fire modes.
Service
The MP18 would prove to be an excellent weapon. Its basic design would influence later submachine gun designs, and copies of it were made in several countries, such as the British Lanchester SMG and the Japanese Type 100. The open bolt design left one problem: if the butt was given a hard knock while the bolt was fully forward and a loaded magazine was inserted, the gun would accidentally fire. Soldiers liked to leave the bolt of their firearm forward so dirt and debris would not enter into the barrel and chamber that would cause a malfunction to occur when the firearm needed to be fired. Later sub-machine gun (SMG) designs like the Sten gun were designed to allow the cocking handle to be pushed inwards therefore locking the closed bolt to the tubular receiver casing. This design change prevented accidental discharges when the bolt was left forward and a loaded magazine was inserted.
