Description
The construction and explosive train of the friction primer is similar to that of the electric except that the explosives are initiated by a serrated gas check which is drawn through friction composition.
Functioning
The firing leaf of the gun engages the button, which is threaded and riveted to the wire. When the lanyard which is attached to the firing leaf is pulled, the wire draws the serrated gas check through the friction compound, causing it to explode. The resulting flame ignites the black powder reinforcing charge and pellets. The primer is a close fit in its seat in the spindle of the breechblock, and the walls of the primer body are made thin so that they are expanded by the gas pressure against the primer seat, thus making a gastight seal. After the gas check is pulled through the friction composition, it seats itself in the cone-shaped recess in the head of the primer body, thus preventing escape of the powder gases through the primer.
See Also
Nothing else to see.
Source(s)
TM 9-1904, Ammunition Inspection Guide (1944)
