The Steyr MPi 69/81 is a 9mm open-bolt submachine gun of Austrian origin. The original MPi 69 version had a unique forward attachment of the sling to the cocking slide, to cock the weapon the sling was grasped and pulled left and down slightly to release the lock, then pulled rearward which cocked the bolt making it ready to fire. The updated MPi 81 model replaced the sling attachment with a plastic handle for a more conventional means of cocking the gun. The sling mount was relocated to a hanger mounted on the barrel retention nut. At the same time a secondary "buffer" spring was added to the recoil mechanism which has the effect of raising the cyclic rate to 700 RPM versus the MPi 69 rate of 550 RPM. Magazines were made in 25rd and 32rd capacities, retained by a heel clip type release. Similar in profile to the Uzi, the Steyr is constructed of a square steel tube upper that contains the bolt and barrel, and the plastic covered sheet steel lower which contains the grip and firing mechanism. A cross-bolt selector has 3 positions, safe, semi, and full auto, although in the full-auto position single shots can still be made by pulling the trigger only halfway.
