Sniper rifles range in caliber (the diameter, or width, of the bullet fired in fractions of an inch) from as small as with the .22 LR (long rifle) bullet fired by many small pistols, to as large as with the .50 Browning Machine Gun (BMG) bullet which is fired by vehicle mounted heavy machine guns. Smaller rounds like the .22 LR are often used at very close range with a sound suppressor (commonly called a silencer) to quickly and quietly break street lights or kill vermin and small animals. The round is generally too weak and has too short of a range for longer range work, or shots on human-sized targets. In contrast, large rounds like the .50 BMG are fired out of very large and heavy sniper rifles that are often used for destroying light vehicles and equipment. They can fire at extreme ranges of over a mile, but generally are too bulky, inaccurate at short ranges, and expensive for general purpose work. 