.177 caliber (4.5mm) is the smallest size of pellets widely used in air guns, and is the only caliber generally accepted for formal target competition. It is also sometimes used for hunting small game, and in field target competition, where it competes with .20 caliber (5 mm) and .22 caliber (5.5 mm) rifles. Compared with a .22 pellet, the .177 travels faster and on a flatter trajectory. This is the reason for it being used in target competitions as the competitor does not have to adjust for drop very much. In hunting, the .177 is in general inferior to .22 calibre pellets as it is smaller thus causing less impact damage. Heavier pellets can however increase its effectiveness.
Steel BB shot is 0.175-inch (4.4 mm) diameter. Some air guns are designed to accept .177 pellets, or .177 lead shot, or .175 steel BBs interchangeably.
Firewood is any wooden material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form, compared to other forms of wood fuel like pellets or chips.
Firewood is a renewable resource. However, demand for this fuel can outpace its ability to regenerate on local and regional level. For example in some places in the world and through history, the demand has led to desertification]citation needed[. Good forestry practices and improvements in devices that use firewood can improve the local wood supplies.
Military technology is the collection of equipment, vehicles, structures and communication systems that are designed for use in warfare. It comprises the kinds of technology that are distinctly military in nature and not civilian in application, usually because they are impractical in civilian application, have no legal civilian usage, or are dangerous to use without appropriate military training.
It is common for military technology to have been researched and developed by scientists and engineers specifically for use in battle by the armed forces. Many new technologies came as a result of the military funding of science. Weapons engineering is the design, development, testing and lifecycle management of military weapons and systems. It draws on the knowledge of several traditional engineering disciplines, including mechanical engineering, electrical engineering, mechatronics, electro-optics, aerospace engineering, materials engineering, and chemical engineering.
Airsoft guns are replica firearms used in airsoft that fire plastic pellets by way of compressed gas or electric and/or spring-driven pistons. These guns are designed to be non-lethal and to provide realistic replicas.
Depending on the mechanism driving the pellet, an airsoft gun can be operated manually or cycled by either compressed gas such as Green Gas (propane and silicone mix) or CO2 or by compressed air via a spring or an electric motor pulling a piston.
Airsoft pellets are spherical projectiles used in Airsoft gun models. Typically made of plastic, they usually measure around 6 mm in diameter, though select models use 8mm, and weigh between 0.12 and 0.48 g, with the most popular weights being 0.12g and 0.20g. Although sometimes called BBs, they are not the same as the 4.5 mm projectiles fired by BB guns.