Described herein are examples of firearms and firearm assemblies. In one example, a firearm assembly for use in a firearm including a breech block, includes safety equipment; a slide stop, wherein the slide stop is adjustable between an arresting position that locks the breech block and a position that does not lock the breech block; and a safety element adjustable relative to the slide stop between a neutral position and secured position, wherein in the secured position if the breech block exerts an operating force on the safety element and the safety element engages the safety equipment, the safety element fixes the slide stop in its arresting position.