US Patent 9109855 Modular buttstock assembly

A modular buttstock assembly that removably mounts to a receiver extension of a firearm may include a main body and a rear body. The main body may have a passage that mates with the receiver extension, while the rear body may be removably coupled to the main body such that any number of swappable, modular rear bodies may be coupled to the main body. The main body may include a toggle assembly with a actuating lever coupled to an bowed or ached actuating spring. The toggle assembly may also include a locking block with a plurality of shafts that distribute the load from the receiver extension to the main body rather than concentrating mechanical stress on a single lock pin.