Lever the power out, and the ratio of output to input force is given by the ratio of the distances from the fulcrum to the points of application of these forces. This is known as the "law of the lever." The mechanical advantage of a lever can be determined by considering the balance of moments or torque, "T", about the fulcrum. where F is the input force to the lever and F is the output force. The distances "a" and "b" are the perpendicular distances between the forces and the fulcrum. Since the moments of torque must be balanced, formula_3 .
Lever action are chambered for 12 gauge smokeless shells, while the Winchester Model 9410 shotgun is available in .410 bore. Lever action Lever action is a type of firearm action which uses a lever located around the trigger guard area (often including the trigger guard itself) to load fresh cartridges into the chamber of the barrel when the lever is worked. This contrasts to bolt-action, semi-automatic, or selective-fire weapons. Most lever-action firearms are rifles, but some lever-action shotguns and a few pistols have also been made. One of the most famous lever-action firearms is the Winchester Model 1873 rifle, but many manufacturers—notably