The Cookson rifle dates from 1750 and features a two-chamber horizontally mounted rotating drum.
When the lever was returned to its original position, the ball dropped into the chamber, and the powder charge lined up behind it.
While most of these guns used gravity to feed the balls into the drum, one specimen, from the Paris museum, used a spring to force them in.
[3] Although other breech loading rifles were introduced in later years, the Cookson-type long arms were unique in their ability to fire multiple shots without reloading.
However, unlike the Kalthoff, the Cookson system had a dangerous flaw in that flame could leak from the firing chamber into the powder magazine, making the gun explode at high risk to the user.