5.56 Headspace Gage

Forster Headspace Gage 5.56 NATO - 1.4736" plus zero minus .0003" (maximum chamber)

…gunsmith knows that proper use of a headspace gage is the most reliable way to test the length of a rifle chamber. "Headspace" is the distance between the face of the breech and the base of the cartridge when the action is closed, and excessive headspace can be dangerous as well as impair accuracy.…