Lever a place to stand, and I shall move the Earth with it' is a remark of Archimedes who formally stated the correct mathematical principle of levers (quoted by Pappus of Alexandria). It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighing more than 100 tons. A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in the hinge or bending in the beam. In this case, the power into the lever equals
Lever action Lever-action designs with strong, rotary locking bolts (such as the Browning BLR with seven locking lugs) safely use very high-powered cartridges like the 300 Winchester mag, 300 WSM and 7 MM Remington magnum. Tilting block designs such as the Savage Model 99 are also strong enough to handle high pressures. Many lever actions have a tubular magazine under the barrel. To operate safely, cartridges for these have bullets with rounded tips, and some use rim-fire primers rather than center-fire primers. The safety problem is that long-range aerodynamic supersonic bullets are pointed. In a tubular magazine the points can accidentally fire