In firearms, tapering refers to components that narrow down like a cone does, hence the name taper. [1] [2] [3] [4]
In barrels, this centralises mass to the operator, not only to reduce perceived weight due to center of mass, but also to improve accuracy/acquisition and stabilise the balance handling of the weapon. In addition, a tapered barrel means that chamber pressures are higher, leading to increased round velocity.
In cartridges, this usually helps in chambering/unloading the weapon. This differs from shouldering/bottlenecking [5] , which only refers to the case head of the cartridge that holds the projectile, whereas tapering usually refers to the angled sides of the cartridge.