FB Glauberyt

The PM-84 Glauberyt is a Polish submachine gun. It is a personal weapon intended for combat and self-defense at ranges up to 150 m with single shot or fully automatic fire mode. It features a compact design, minimum overall dimensions, small weight, very good accuracy, and fire stability. It is designed for heavy weapons platoons personnel and reconnaissance detachments, special anti-terrorist and police troops.
In service with the Polish military and police it replaced the earlier PM-63 RAK submachine gun.
Operation.
The Glauberyt is a select-fire, straight blowback-operated firearm that fires from the closed bolt position. Its design influence can be seen to mimic the Uzi. However it features a last shot bolt hold open/release like modern service pistols unlike any other submachine guns of its time. The PM-84/PM-84P also features ambidextrous charging handles on both sides (influenced by the vz.61 Škorpion). A two-bar retractable buttstock tucks right into the side of the weapon. The magazine release is in the heel of the pistol grip. The Glauberyt feeds from 15-round flush magazines and 25-round extended magazines. Fire selector Z = SAFE, P = SEMI, C = FULL AUTO, and sits above rear of the pistol grip. When the firearm is on SAFE, the bolt is locked and prevented from moving. A folding fore grip rests in front of the trigger guard (in the style of the PM-63 RAK), and an optional tactical flashlight/laser grip can also be mounted, replacing the folding fore grip.
Modern PM-98/PM-06 variants utilize a thumb magazine release. A new slot in the magazine is required to be cut out to work in the later Glauberyts.