Pistol-whipping

[1] Such a practice dates to the time of muzzle loaders, which were brandished in such fashion in close-quarters combat once the weapon's single projectile had been expended.

The term buffaloing is documented as being used in the Wild West originally to refer to the act of being intimidated or cheated by bluffing.

Single-shot weapons that were tedious to reload were used to strike opponents directly in close-quarters combat after their projectile had been expended.

It was entirely up to circumstance whether the user had time or chose to reverse the gun in their hand and strike a blow with its handle or merely swung the heavy weapon as a club or baton holding it normally.

Author Paul Wellman notes that clubbing an opponent with the butt of a gun held by its barrel, as seen in some Westerns, is problematic.