Abstract: A muzzle loader AR upper receiver can include a muzzle loader AR pattern upper receiver configured to be coupled with an AR pattern lower receiver. The muzzle loader AR pattern upper receiver includes a body with a barrel opening. A muzzle loader barrel is coupled to the barrel opening of the muzzle loader AR pattern upper receiver. A muzzle loader AR rifle can include the muzzle loader AR pattern upper receiver and the AR pattern lower receiver coupled to the muzzle loader AR pattern upper receiver. A method of forming a muzzle loader rifle can include: providing a muzzle loader AR upper receiver; and coupling the muzzle loader AR upper receiver to an AR pattern lower receiver. A muzzle loader kit can include the muzzle loader AR pattern upper receiver and any other component, such as a ramrod, barrel, or AR pattern lower receiver.

Abstract: A bolt action AR rifle can be prepared using a standard AR lower assembly and coupling it to a bolt action upper assembly. The bolt action upper assembly has a bolt action receiver containing a bolt. The method of forming a bolt action AR rifle can include: providing the bolt action upper receiver assembly; providing the standard AR lower AR receiver assembly having a pivot pin and takedown pin; inserting the pivot pin into the pivot pin receiver hole; pivoting the bolt action upper receiver assembly at the pivot pin until the takedown pin is aligned with the takedown pin receiver hole; and inserting the takedown pin into the takedown pin receiver hole.

Abstract: A bolt action AR rifle can be prepared using a standard AR lower assembly and coupling it to a bolt action upper assembly. The bolt action upper assembly has a bolt action receiver containing a bolt. The method of forming a bolt action AR rifle can include: providing the bolt action upper receiver assembly; providing the standard AR lower AR receiver assembly having a pivot pin and takedown pin; inserting the pivot pin into the pivot pin receiver hole; pivoting the bolt action upper receiver assembly at the pivot pin until the takedown pin is aligned with the takedown pin receiver hole; and inserting the takedown pin into the takedown pin receiver hole.

Abstract: A bolt action AR rifle can be prepared using a standard AR lower assembly and coupling it to a bolt action upper assembly. The bolt action upper assembly has a bolt action receiver containing a bolt. The method of forming a bolt action AR rifle can include: providing the bolt action upper receiver assembly; providing the standard AR lower AR receiver assembly having a pivot pin and takedown pin; inserting the pivot pin into the pivot pin receiver hole; pivoting the bolt action upper receiver assembly at the pivot pin until the takedown pin is aligned with the takedown pin receiver hole; and inserting the takedown pin into the takedown pin receiver hole.