Federal Cartridge Company

Federal-hoffman, Inc.

John M Melberg

Jack A Erickson

Joel Lee Sandstrom

John M Hallis

Robert L Kramer

A lead-free, heavy-metal free rim-fire priming composition consisting essentially of diazodinitrophenol (DDNP) as a primary explosive, a low percentage of a secondary sensitization explosive (tetracene), with a high percentage of abrasive (ground glass) and a very low percentage of an effective lead-free, heavy-metal-free oxidizer. A strong binder is added to aid in the installation and retention of the composition within the rim of the casings. A dye is also included for the sole purpose of facilitating visual inspection within the casing after installation of the composition within the rim. The high percentage by weight of the ground glass (46-60%) in combination with DDNP is of principal importance. The preferred mix is comprised of 29.8% of DDNP, 4.0 tetracene, 57.0% ground glass, and 7.5% potassium nitrate with 1.5% gum tragacanth added as a binder and 0.2% Prussian Blue as a dye.

Lead-free, heavy-metal-free rim-fire priming composition dedicated for

A lead-free rim-fire primer mix which utilizes cupric azide, a highly sensitive chemical, as the primary explosive in lieu of lead styphnate. The cupric azide is mixed with carefully selected proportions of nitrocellulose, tetracene, fine particles of ground glass and a binder, typically gum tragacanth. When mixed in the proper proportions, this mix has the required sensitivity, stability, and non-hygroscopicity for regular commercial rim-fire ammunition. The tetracene is not required as a sensitizer, but is used as an ignition aid. The preferred range of percentages are 10-36% by weight of cupric azide, 5-10% by weight of tetracene, 15-30% by weight of nitrocellulose, 20-50% by weight of glass, and 1-2% by weight of a suitable gum.

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Andover, MN, United States of America

John M Melberg