Patent ID: 7810271

Claim:
A modular rifle comprising: a lower receiver assembly that can be separated into a lower receiver portion and a magazine well portion; a coupling mechanism configured to releasably couple the portions of the lower receiver assembly together, the coupling mechanism including an aperture and a pin that can be moved into and out of the aperture; and an upper receiver that is releasably coupled to the lower receiver assembly, wherein: a rearward side of the magazine well portion has an indent shaped to mate with a ledge on a forward side of the lower receiver portion, the indent and the ledge aligning the magazine well portion and the lower receiver portion in axial and vertical directions, and the rearward side of the magazine well portion has a slot shaped to mate with a projection on the forward side of the lower receiver portion, the slot and the projection aligning the magazine well portion and the lower receiver portion in a lateral direction.