What is "rammers"

Usage examples of "rammers".

The rammers drew their horses aside so that Drehkos and most of his force might ride through the archway, hooves booming hollowly on the shattered portal.

The blades stabbed at the few Frenchmen who tried to swing rammers at the British Riflemen.

They had pulled the cannon back, and, through the grunting sound of the groans about him, the lieutenant could distinctly hear the thud and punch of the rammers, and he knew they were going to shoot again.