The Model 1866, was nicknamed "Yellow Boy" because of its "brass" receiver (it was actually made of a type of bronze called gunmetal); it was a lever-action repeating carbine, that is, it allowed several shots to be fired before reloading, dislodging the used casing and replacing it with a new one by actuating a lever attached to the trigger guard; hence the term "repeating rifle". Its operation consisted of a horizontal movement closure that had the needle in line inside; the lower lever, when actuated, unlocked the breech, then moved it backwards, uncovering the chamber, giving space to a lifting tile and mounting the firing pin from behind. At the end of its rearward travel, the breech caused a bullet to travel from the magazine to the lifting tile, and then the forward reciprocating mo