Abstract: A firearm receiver with an extended bridge is created to prevent the fully automatic fire of an assault rifle. The extended bridge receiver has a narrowed magazine well for a single stack removable magazine, safety catch with one or more grooves on its lower left hand side, new sporting stock where grip part and butt-stock part form one unit and barrel extension permanently attached to the muzzle. The receiver can be configured with a rivet on the bridge in a location that prevents backward turning of the safety catch, where the modified safety catch has two positions (i.e. safe and fire), rather than the three positions consistent with a fully automatic firearm. In a second version, the extended bridge lacks a release lever groove. In yet another version, an inseparable, double stack magazine box is used.

Abstract: A semi-automatic pistol is created by the modification of a fully automatic sub-machine gun Sa vz. 61. The semi-automatic pistol is constructed partly from original parts of the Sa vz. 61 sub-machine gun, i.e. barrel, receiver, trigger, trigger lever and pistol grip, partly from modified parts of Sa vz. 61 sub-machine gun, i.e. hammer, interrupter and bolt, and partly from newly manufactured parts, i.e. semi-automatic frame without a groove in the bridge for the release lever and openings in rear stop for retarder assembly and without rails for folding stock on the outside of the rear wall, and a new safety lever with holes and grooves in such a positions that only semi-automatic fire is possible in its forward position. Some parts of the Sa vz. 61 sub-machine gun are removed completely, i.e. original frame, original safety lever, release lever, folding stock and retarder group (bolt hook, weight, counterweight, spring).

Abstract: A firearm receiver with an extended bridge is created to prevent the fully automatic fire of an assault rifle. The extended bridge receiver has a narrowed magazine well for a single stack removable magazine, safety catch with one or more grooves on its lower left hand side, new sporting stock where grip part and butt-stock part form one unit and barrel extension permanently attached to the muzzle. The receiver can be configured with a rivet on the bridge in a location that prevents backward turning of the safety catch, where the modified safety catch has two positions (i.e. safe and fire), rather than the three positions consistent with a fully automatic firearm. In a second version, the extended bridge lacks a release lever groove. In yet another version, an inseparable, double stack magazine box is used.

Abstract: A trigger mechanism of a firearm is modified by having its right hand side (in the direction of fire) arm, removed, while leaving the left hand side arm intact, which eliminates its co-operation with a right hand side striker catch, consequently preventing an attempt to reinstall the removed parts. In a second version, the trigger mechanism is manufactured without its right arm. The safety catch is modified by inserting a groove near a far end such that it is configured to receive a firearm interrupter, enabling its manning and firing of a single shot when the firearm is in the horizontal position, while preventing the firearm from shooting when in a vertical position.

Abstract: A semi-automatic sporting rifle is created by the modification of a fully automatic assault rifle Sa vz. 58. The semi-automatic rifle is constructed partly from original parts of the Sa vz. 58 assault rifle, i.e. bolt carrier, locking piece, striker, return mechanism, barrel, trigger, interrupter and left hand side striker catch, partly from modified parts of Sa vz. 58 assault rifle, i.e. bolt, trigger mechanism feather and safety catch and partly from newly manufactured parts, i.e. semi-automatic receiver with a narrowed magazine well for a single stack removable magazine with extended bridge, safety catch with one more groove on its lower left hand side, new sporting stock where grip part and butt-stock part form one unit and barrel extension permanently attached to the muzzle. Some parts of the Sa vz. 58 assault rifle are removed completely, i.e. muzzle thread protector, bayonet lug, original receiver, original stock, pistol grip, release lever, trigger lever and right hand side striker catch.

Abstract: A semi-automatic sporting rifle is created by the modification of a fully automatic assault rifle Sa vz. 58. The semi-automatic rifle is constructed partly from original parts of the Sa vz. 58 assault rifle, i.e. bolt carrier, locking piece, striker, return mechanism, barrel, trigger, interrupter and left hand side striker catch, partly from modified parts of Sa vz. 58 assault rifle, i.e. bolt, trigger mechanism feather and safety catch and partly from newly manufactured parts, i.e. semi-automatic receiver with a narrowed magazine well for a single stack removable magazine with extended bridge, safety catch with one more groove on its lower left hand side, new sporting stock where grip part and butt-stock part form one unit and barrel extension permanently attached to the muzzle. Some parts of the Sa vz. 58 assault rifle are removed completely, i.e. muzzle thread protector, bayonet lug, original receiver, original stock, pistol grip, release lever, trigger lever and right hand side striker catch.

Abstract: A semi-automatic sporting rifle is created by the modification of a fully automatic assault rifle Sa vz. 58. The semi-automatic rifle is constructed partly from original parts of the Sa vz. 58 assault rifle, i.e. bolt carrier, locking piece, striker, return mechanism, barrel, trigger, interrupter and left hand side striker catch, partly from modified parts of Sa vz. 58 assault rifle, i.e. bolt, trigger mechanism feather and safety catch and partly from newly manufactured parts, i.e. semi-automatic receiver with a narrowed magazine well for a single stack removable magazine with extended bridge, safety catch with one more groove on its lower left hand side, new sporting stock where grip part and butt-stock part form one unit and barrel extension permanently attached to the muzzle. Some parts of the Sa vz. 58 assault rifle are removed completely, i.e. muzzle thread protector, bayonet lug, original receiver, original stock, pistol grip, release, lever, trigger lever and right hand side striker catch.

Abstract: A semi-automatic sporting rifle is created by the modification of a fully automatic assault rifle Sa vz. 58. The semi-automatic rifle is constructed partly from original parts of the Sa vz. 58 assault rifle, i.e. bolt carrier, locking piece, striker, return mechanism, barrel, trigger, interrupter and left hand side striker catch, partly from modified parts of Sa vz. 58 assault rifle, i.e. bolt, trigger mechanism feather and safety catch and partly from newly manufactured parts, i.e. semi-automatic receiver with a narrowed magazine well for a single stack removable magazine with extended bridge, safety catch with one more groove on its lower left hand side, new sporting stock where grip part and butt-stock part form one unit and barrel extension permanently attached to the muzzle. Some parts of the Sa vz. 58 assault rifle are removed completely, i.e. muzzle thread protector, bayonet lug, original receiver, original stock, pistol grip, release, lever, trigger lever and right hand side striker catch.

Abstract: Converting a functioning assault rifle to an inoperative dummy gun suitable for collectors by replacing the receiver with a receiver filled with a solid material. The filled spaces of the receiver prevent the cooperative operation with the other components of the gun. The dummy receiver is externally indistinguishable from the functioning receiver. Thus, a model rifle is converted for collectors so as to be unrecognizable from the functioning gun. To accommodate the filled spaces in the receiver, the lower part of the cooperating bolt carrier is milled off. The dummy receiver may include an affixed rear sight base.