| 摘要 |
A one-piece plastic wad structure for use with a shotshell, the wad structure having a projectile-receiving pocket, an obturating pocket, and a transverse wall integral with the pockets and separating one pocket from the other. The projectile pocket and obturating pocket have side walls of solid plastic, and at least a portion of the transverse wall is foamed plastic. The transverse wall is of substantial thickness so as to cushion the shot charge when a cartridge containing the wad is fired. The wad structure is formed by injecting a molten mixture of a resinous material and a foaming agent into a mold cavity, cooling the injected mixture so as to partially solidify the mixture in the cavity, and then reducing pressure in the cavity by enlarging its volume to permit the transverse wall portion of the injected mixture to foam in situ. |
