Abstract: A system that converts an original equipment (OEM) AR-15 rifle to a rifle capable of firing cartridges of at least two different calibers. Two or more barrel liners are provided for cartridges of differing calibers. Each liner is insertable through a rear opening of an upper receiver portion of the rifle and into a smooth bore barrel of a modified barrel assembly. Each liner comprises a tube portion having a longitudinal bore and a head portion with an opening that communicates with said bore. An adapter bolt carrier assembly is substituted for the OEM AR-15 bolt carrier assembly. The substituted assembly includes a bolt that carries the firing pin and is slidably mounted on a rail guide. A front end of the rail guide has a tongue extension with a slot that receives a pin attached to a rear end of a liner head. A support rail is fixed to a rear end of the rail guide. A spring extends from the support rail to the bolt, thereby pressing the bolt against the liner head.

Abstract: The present invention discloses a firearms safety system for adapting conventional handheld firearms to fire non-deadly simulated training ammunition, which system provides a series of gas relief ports and passages to prevent the successful firing of live ammunition in the firearm. The system can be advantageously utilized in modified M16 type military type rifles which have been previously adapted to fire pistol cartridges such as the 9 mm and .40 S&W calibers. The system is also particularly advantageous for use in handheld firearms such as pistols and revolvers, as well as in conventional long guns such as bolt action rifles, and all shotguns.

Abstract: The present invention discloses a firearms safety system for adapting conventional handheld firearms to fire non-deadly simulated training ammunition, which system provides a series of gas relief ports and passages to prevent the successful firing of live ammunition in the firearm. The system can be advantageously utilized in modified M16 type military type rifles which have been previously adapted to fire pistol cartridges such as the 9 mm and .40 S&W calibers.

Abstract: A modified M16 pistol capable of firing rifle cartridges therein in automatic or semi-automatic mode, which pistol is based upon modified M16 upper and lower assemblies, with a pistol barrel, an M16 gas actuation system, and a spring-biased buffer system mounted on top of the M16 upper receiver assembly.

Abstract: An M16 type rifle is disclosed having a gas piston assembly with a relatively large piston area and sufficient stroke to actuate the M16 bolt carrier assembly in order to allow the M16 rifle to be chambered for short low-pressure pistol cartridges such as the 45 ACP, 10 mm, and 40 S&W. The gas piston assembly provides relatively constant contact between the piston rod and the gas carrier key of the conventional M16 bolt carrier assembly.