Wiktionary
buttstroke
n. (context military slang English) The act of striking a person with the butt of a rifle
Wikipedia
Usage examples of "buttstroke".
He used a buttstroke instead, and felt the big end of his piece slam the side of the Jap’s head.
Now he got to buttstroke one of the breed of stuck-up riche hombes bastards.
He caught it on the bayonet, pivoted the rifle and buttstroked the wog in the face.
She'd reached through the fencing that saved her life when it absorbed the reflexive buttstroke that would have crushed her sternum and flung her backwards.
Ryan swept the Steyr around to buttstroke the deputy, breaking the back of the man's head.