Low toxicity primer compositions for reduced energy ammunition

Abstract

A primer composition with reduced toxicity suited for reduced-energy ammunition comprises bismuth (III) oxide as the principal oxidizer and contains a portion of propellant composition mixed therein. This composition may also be used in a cartridge which is otherwise substantially free of any other propellant compound and preferably produces a residue which is substantially free of toxic substances.

Description

FIELD OF THE INVENTION[0001]This invention relates to primer compositions for use in low energy ammunition intended for training and preferably having reduced toxicity.BACKGROUND TO THE INVENTION[0002]There is an ongoing concern that much of the ammunition produced in the world today contains toxic components, such as heavy metals, that contaminate firing ranges and other locations where ammunition is used in training. In order to reduce the environmental impact from training with traditional ammunition, new compositions that are relatively free of contaminants are sought.[0003]Both the propellant and primer mixtures used in ammunition are potential sources for such contaminants. Various patents disclose propellant formulations that have reduced amounts of contaminants. Formulations for a primer that do not comprise toxic components are described herein.[0004]A particular application for a primer with reduced toxicity is its use in the class of ammunition which may be described as b...

AI Technical Summary

Benefits of technology

[0022]The primer mixture is preferably characterized by the presence of a percussion initiated, shock-sensitive primary explosive, a combustible fuel, the use of bismuth (III) oxide as an oxidizer and the presence of a further propellant composition mixed with the balance of the primer composition to form the final primer mixture. According to further preferred variants the primer mixture may also include the following constituents, individually or collectively: a secondary explosive, an explosive sensitizer to increase sensitivity to friction / shock and a frictionator which improves the heat generation of the reaction.

[0024]Further, and as an additional preferred variant of the invention, the residual products after firing a cartridge containing the primer composition according to the invention are substantially free of toxic elements and components that have historically been associated with cartridge chemistry such as, for example, mercury, lead, barium, antimony, beryllium, cadmium, arsenic, chromium, selenium, tin, thallium as well as similar toxic substances.

[0031]Diazodinitrophenol (DDNP), also known as “dinol”, is used as the preferred primary explosive and is selected based on its favourable historic performance in other types of reduced-toxicity primers and because it is readily produced from available raw materials.

[0036]Tetrazene is added as an explosive sensitizer to increase sensitivity to percussion.

[0038]Binder is optional but preferably provided in an effective amount to consolidate the components and reduce the tendency for the composition to absorb moisture. In this case it was provided in the form of Acronal™, a polymerized vinyl compound. Such a binder may be in the form of any suitable water-soluble composition that does not react adversely with the other components of the invention and will perform its function of consolidating the final primer composition.

Problems solved by technology

There is an ongoing concern that much of the ammunition produced in the world today contains toxic components, such as heavy metals, that contaminate firing ranges and other locations where ammunition is used in training.

However, this primer mixture is not intended for use in low-energy ammunition.

'199, “rimfire ignition differs significantly from centerfire ignition so it is apparent that a primer composition which is suitable for centerfire cartridges may not perform adequately in rimfire applications.” Conversely, rimfire primer compositions would not be expected to perform adequately in centerfire cartridges.

Additionally, the primer mixture described in this reference is not intended for use in low-energy ammunition.

However, no suggestion is made in this reference of incorporating propellant material in the primer composition.

Images