Abstract: A modular bolt assembly may include a bolt body, a striker assembly, and one or more removable bolt, head having a floating fixing pin, The removable bolt head may have a cartridge engagement surface, a back end that removably mates with a bolt body, and a floating firing pin with a front end that contacts a cartridge primer, and a rear end that receives force from the striker assembly. Bolt heads may be included for different caliber cartridges, allowing the modular bolt assembly to be used with different types of ammunition, the floating firing pin prevents the striker assembly from directly contacting a chambered round without the bolt head, thereby preventing catastrophic failure during use if a boll head is not present and properly positioned.

Abstract: A semi-automatic rifle is configured to fire single rounds of ammunition via a magazine or a belt of ammunition. A receiver cover pivots open to receive the first round of a belt of ammunition or a magazine can be inserted in a magazine well. The rifle operates using a closed bolt firing cycle, with a sliding hammer that, on its return from recoil after firing a first round, is caught by a sear regardless of whether the trigger is still in the pulled position. The trigger must be fully released before a second round can be fired.

Abstract: A reversible modification to the gas block of a machine gun reduces the rate of fire to the machine gun's design rate for use when a suppressor has been added to the barrel and which suppressor would, without the present modification, elevate the firing rate from the machine gun's design rate. The modification is the use of a stem inserted into the bore of the gas block nozzle to further limit the combustion gas being delivered to the machine gun's operating group. A hole formed in the stem restricts gas flow. The stem seats against the gas block nozzle and is held in place by the cap covering the gas block but may alternatively be held in place in several alternative ways described. Removal of the cap allows the stem to be removed from the gas block when the suppressor has been removed from the machine gun barrel.

Abstract: A sound suppressor for a firearm with a high rate of fire, such as a machine gun, conceals the location of the firearm during heavy use by rapidly dissipating heat through a foamed carbon core. A sound suppressing baffle core is coaxially located within a tubular housing, having flared ends extending beyond the core. An inlet nozzle and exit place close the ends of the suppressor and are held in place with threaded collars. The terminal portions of the collars are beveled, as are the corresponding terminal portions of the nozzle and end plate, and are used to capture the flared portions of the ends of the tubular housing. Diagonally opposing recesses in the collars enable their removal with a spanner wrench, along with the other components for maintenance and replacement. The suppressor lasts longer and has a less visible heat signature used in sustained fire on a machine gun.