Patent ID: 8276305

Claim:
A unitary shot pattern control system for a multiple projectile load firing weapon comprising an inner substantially cylindrical chamber defined by a sidewall having a rear opening and a muzzle opening, wherein the multiple projectile load comprises multiple projectiles sealed by a wad; the inner cylindrical chamber is divided at a median transverse plane into a forward section that terminates at the muzzle opening and a rear section that terminates at the rear opening, and a plurality of longitudinal channels extend from the rear section into the forward section; the channels are dimensioned such that when the multiple projectile load is fired, the resulting propulsion gas is initially sealed behind a wad containing the multiple projectile load until the wad has advanced, beyond the beginnings of the longitudinal channels; the channels are positioned such that once the wad has advanced beyond the beginnings of the longitudinal channels, a portion of the propulsion gas laterally expands into the channel; and the forward section of the inner chamber is dimensioned to sealingly engage the wad after it has advanced past the radial vents to cause gas pressure in the channels to build.