Method of electroforming gun barrels and liners

Claim 1

THE METHOD OF MANUFACTURING A GUN BARREL HAVING A RIFLED BORE OUT OF METALS THAT ARE HIGHLY RESISTANT TO EROSION AND CORROSION BUT ARE TOO HARD TO MACHINE OR CAST CONVENIENTLY WHICH COMPRISES MAKING A METALLIC "NEGATIVE" FORM WHOSE EXTERNAL DIMENSIONS SUBSTANTIALLY CORRESPOND TO REQUIRED INTERNAL DIMENSIONS FOR THE DESIRED GUN BARREL''S RIFLED BORE, POLISHING SAID "NEGATIVE FORM TO A SMOOTH FINISH, PLATING UPON THE OUTER SURFACE OF SAID "NEGATIVE" FORM A THINN LAYER OF A FUSIBLE METAL WHICH DOES NOT READILY THEREAFTER ELECTROPOLISHING THE FUSIBLE METALCOATED "NEGATIVE" FORM TO A BRIGHT AND SMOOTH FINISH, THEREAFTER ELECTROPLATING THE METAL FROM WHICH SAID GUN BARREL IS TO BE MADE TO A DESIRED PART OF THE DESIRED TOTAL THICKNESS UPON THE OUTER SURFCE OF SAID FUSIBLE METAL-COATED "NEGATIVE" FORM AT A TEMPERATURE BELOWTHE MELTING POINT OF SAID FUSIBLE METAL COATING, THEREAFTER MACHINING SMOOTH THE OUTER SURFACE OF THE METAL WHICH HAS BEEN THUS ELECTROPLATED UPON THE FUSIBLE METAL-COATED "NEGATIVE" FORM IN ORDER TO ELIMINATE THE CONTOUR OF THE UNDERLYING LANDS AND GROOVES FROM THE SUBSEQUENT PLATING, THEREAFTER RESUMING ELECTROPLATING THE METAL FROM WHICH SAID GUN METAL IS TO BE MADE AS AFORESAID UNTIL THEDESIRED TOTAL GUN BARREL THICKNESS PLUS A MARGIN FOR FINAL MACHINING HAS BEEN REACHED, THEREAFTER HEATING THE THUS ELECTROLATED "NEGATIVE" FORM TO A TEMPERATURE HIGH ENOUGH TO MELT AND ELIMINATE SAID FUSIBLE METAL COATING FROM SAID "NEGATIVE" FORM, THEREAFTER EXTRACTING SAID "NEGATIVE" FORM FROM THE RESULTANT GUN BARREL THAT HAS BEEN ELECTROFORMED THEREAROUND, AND THEN MACHINING THE OUTSIDE WALL SURFACE OF THE RESULTANT GUN BARREL TO THE DESIRED OVERALL CROSS-SECTIONAL DIMENSIONS.