Dow Corning Corporation

Other

David C DeLeeuw

Jonathan Lipowitz

Paul P Lu

James A Rabe

A muzzle-loading firearm includes a breech plug for mating, non-threaded engagement with a housing located at the breech end of an axial bore of the firearm barrel. The plug includes a cylindrically-shaped body member having opposite first and second ends and an outer surface between the ends and configured so that when the plug is positioned within the housing, the outer surface is spaced close to the inside surface of the housing to facilitate insertion and removal of the plug from the housing. The body member is formed with a primer chamber for receiving and retaining a primer or a percussion cap at the first end, and a passageway for fluidly communicating the primer chamber with a powder charge at the second end. The body member may have a powder chamber for receiving and retaining at least part of a powder charge at the second end when the firearm is loaded. The material and dimensions of the body member may be such that the body member deforms radially outwardly so that the outer surface of the body member and the inside surface of the housing form an essentially gas-tight seal during firing. The powder chamber contains much of the powder residue generated by the firing. In order to insure that the muzzle-loader cannot be readily used as, or converted to, a breech-loading firearm, different muzzle-loader/breech plug design features are presented. With one design feature, the maximum cross-sectional inner dimension of the housing is less than the diameter of the bore of the barrel. With another design feature, alignment of the firing pin and primer chamber (or hammer and percussion cap holder) is along an axis not centered with the axial bore of the barrel. The cross-sectional shape of the housing and breech plug may be non-cylindrical. For example, the cross-sectional shape can be oblong, essentially triangular, etc. Thus, conventional, breech-loading ammunition will not be effectively usable in the muzzle-loading firearm.

Muzzle-loading firearm and easily removable breech plug for use therewith

A process for the preparation of substantially polycrystalline silicon carbide fibers is provided. The fibers may be fabricated to have a small diameter and are thermally stable at high temperatures. The process is carried out by initially forming fibers from a preceramic polymeric precursor comprising methylpolydisilylazane resins. The fibers are then infusibilized to render them nonmelting followed by a pyrolysis step in which the fibers are heated to a temperature in excess of 1600.degree. C. in a nonoxidizing atmosphere to form substantially polycrystalline silicon carbide fibers. The substantially polycrystalline silicon carbide fibers which are formed by the process of the present invention have at least 75% crystallinity and have a density of at least about 2.9 gm/cc. The polymeric precursor or the fibers contain, or have incorporated therein, at least about 0.2% by weight boron. This incorporation of boron may be accomplished either prior to or during formation of the fibers or during at least one of the infusibilizing or pyrolyzing steps of the process.

Preparation of substantially polycrystalline silicon carbide fibers from

This invention relates to the preparation of thermally stable, substantially polycrystalline silicon carbide ceramic fibers derived from a polycarbosilane resin. The unexpected thermal stability of these fibers is achieved by the incorporation of boron prior to ceramification.

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Midland, MI, United States of America

David C DeLeeuw