A firearm grip includes first and second ends, a gap between the first and second ends, and a bolt aperture extending from the first end to the gap. The first end receives a firearm receiver. The bolt aperture receives a bolt to attach the firearm grip to the firearm receiver. The gap may be a thumbhole. The bolt aperture may extend through an upper portion of the firearm grip. A method of assembling a firearm includes positioning a firearm receiver adjacent to a first end of a firearm grip and positioning a bolt within a bolt aperture of the firearm grip. The bolt extends into the firearm receiver. The firearm receiver may be a shotgun receiver. The bolt may be inserted into the bolt aperture through a gap in the firearm grip. The bolt may be countersunk within a surface of the gap.