Letter: M

The resultant noise that occurs at the muzzle of a firearm when the projectile leaves the muzzle and hot gases are released.

A muzzle attachment or feature that uses the propellant combustion gas with the desired effect of redirecting the recoil.

A cover put on the muzzle end of a barrel to keep out foreign matter.

A projectile’s energy at the time it leaves the muzzle of a gun.

The illumination which is the result of the expanding gases from the burning propellant particles emerging from the barrel behind the projectile and uniting with oxygen in the air.

A device put on the end of a barrel with a hole concentric with the bore to admit a cleaning rod and keep the rod from wearing the rifling in this critical area. Not used on guns cleaned from the breech end.

A second, smaller bead sight near the middle of the barrel or barrels of some shotguns.

An angular measurement method used to describe accuracy capability. A minute of angle is one sixtieth of a degree, and subtends 1.047 inches at 100 yards, which for practical shooting purposes is considered to be one inch. A minute of angle group, therefore, equals one inch at 100 yards, two inches at 200 yards, etc.

A conical nosed lead bullet, slightly under bore diameter, incorporating a hollow base, designed to expand into the rifled bore upon firing for gas sealing purposes without the use of a patch.

The angle subtended by one unit at 1000 units.