Adjustable volume shot wad structure and method of assembling the same

An improved shot wad structure for use in a shotshell with shot pellets having a hardness generally at least equal to that of the barrel of a gun in which the shotshell is to be fired, said wad structure comprising:

• (a) an outer body being formed of a soft, low tensile strength material and having a cup-like cross-sectional shape and a bottom portion capable of obturating the combustion gases produced in the gun barrel when the shotshell is fired;
• (b) an inner body having a cup-like cross-sectional shape for receiving and supporting a column of shot and being movably insertable within said outer body to any one of a number of different depths therein at which any one of a corresponding number of different volumes of space is defined within said outer body for containing a column of shot having any one of a number of different shot load sizes, said inner body being formed of a tough, high tensile strength material capable of withstanding compressive forces generated by acceleration of the shot, when the shotshell containing said wad structure is fired in the barrel of the gun, so as to protect the gun barrel from being scored by the shot;
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• (c) a wad insert disposed within said outer body between said bottom portion thereof and said inner body inserted therein, said wad insert being formed of a material which is one-way crushable for permitting insertion of said inner body within said outer body to said any one of said number of different depths therein, said crushed material having sufficient compressive strength to support said inner body at said any one of said different depths within said pocket of said outer body.

Method of assembling a shot wad structure for establishing a preselected volume of space in which to contain a column of shot of a desired size in said wad structure, comprising the steps of:

• (a) providing an outer wad cup having a bottom portion capable of obturating combustion gases produced when a shotshell containing said wad structure is fired and a sidewall which together with said bottom portion defines a pocket open at one end;
• (b) providing an inner wad cup having a bottom and sidewall which define a cavity open at one end for receiving and supporting a column of shot, said sidewall of said inner cup being shorter than said sidewall of said outer cup, said inner cup being movably inserted into said pocket of said outer cup and capable of withstanding compressive forces generated by acceleration of the column of shot when a shotshell containing said wad structure is fired;
• (c) providing a plastic wad insert disposed within said pocket of said outer cup above said bottom portion thereof and below said inner cup inserted within said pocket of said outer cup, said wad insert being formed of a foam material which is non-resilient and one-way crushable for permitting further insertion of said inner cup into said pocket of said outer cup to any one of a number of different depths therein, said foam material once crushed having sufficient compressive strength to support said inner cup at said any one of said different depths within said pocket of said outer cup;
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• (d) crushing of said wad insert to an extent which allows insertion of said inner cup to a desired one of said number of different depths therein at which a desired one of a corresponding number of different volumes of space is defined within said outer cup for containing a column of shot having a desired one of a number of different shot load sizes.