A kit for modifying a firearm includes an adapter, and the adapter includes an external threaded surface configured to detachably couple to an internal threaded surface of a receiver of the firearm. An adapter bore is disposed opposite the external threaded surface, and the adapter bore is configured to receive a barrel of the firearm. The kit further includes a securing element, and the securing element includes a securing element bore configured to receive the barrel. The securing element is configured to detachably couple to the adapter and thereby secure the barrel to the adapter.

A firearm with a cartridge has a barrel with an inside surface, a barrel length that is measured starting from a chamber to a barrel muzzle, and a barrel shaft, wherein the cartridge has a single, sabot-free projectile with a peripheral surface. A gap that is open end-to-end in the direction of the barrel shaft is present along at least 90% of the barrel length and over at least 90% of the circumference of the projectile between the peripheral surface of the projectile and the inside surface of the barrel.

A tubular assembly for attaching accessories to gun barrels. The assembly includes a first tubular, including first interior threads on an interior surface thereof and a collet on a first end thereof. The assembly includes a second tubular, including first exterior threads on an exterior surface thereof. The first exterior threads mate with the first interior threads. The second tubular includes a ridge of knurls on the exterior surface thereof. The ridge of knurls is adapted to frictionally engage the collet when the first tubular and the second tubular are assembled.

Disclosed herein is a test gun barrel for use with a long range projectile testing system. The test gun barrel comprising a main gun barrel and a gun barrel extension. The main gun barrel and gun barrel extension each include a joint end having aligning cylinders and bores to properly align the main gun barrel to the extension prior to engaging threaded coupling. A seal capable of being inspected is made once main gun barrel is fully coupled to gun barrel extension.

The inventive technology comprises a novel thermal indicator system that incorporates one or more thermogenic compounds that may be applied to a gun component and indicate the temperature of a gun component during and after use. This novel thermal indicator system may indicate the temperature at which the gun component will cause burns, is unsafe to store, or if a pre-determined threshold temperature has been reached resulting in a loss of firing accuracy, as well as imminent, or actual component failure.

The inventive technology comprises a novel thermal indicator system that incorporates one or more thermogenic compounds that may be applied to a gun component and indicate the temperature of a gun component during and after use. This novel thermal indicator system may indicate the temperature at which the gun component will cause burns, is unsafe to store, or if a pre-determined threshold temperature has been reached resulting in a loss of firing accuracy, as well as imminent, or actual component failure.

An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

The inventive technology comprises a novel gun barrel thermal indicator system that incorporates one or more thermogenic compounds that may be coupled to a gun barrel and indicate the temperature of a gun barrel during and after use. Additional embodiments may comprise a digital gun barrel thermal indicator system that may be coupled to a gun barrel and digitally indicate the temperature of a gun barrel during and after use. This novel gun barrel thermal indicator system may indicate the temperature at which the gun barrel will cause burns, is unsafe to store, or if a pre-determined threshold temperature has been reached resulting in a loss of firing accuracy, as well as imminent and/or actual barrel failure.

The inventive technology comprises a novel gun barrel thermal indicator system that incorporates one or more thermogenic compounds that may be coupled to a gun barrel and indicate the temperature of a gun barrel during and after use. Additional embodiments may comprise a digital gun barrel thermal indicator system that may be coupled to a gun barrel and digitally indicate the temperature of a gun barrel during and after use. This novel gun barrel thermal indicator system may indicate the temperature at which the gun barrel will cause burns, is unsafe to store, or if a pre-determined threshold temperature has been reached resulting in a loss of firing accuracy, as well as imminent and/or actual barrel failure.