Munitions round for barrel-type weapons

Claim 1

A munitions round for a barrel-type weapon, comprising: an elongated casing having a closed rear end and an open forward end; a fin-stabilized subcaliber elongated projectile disposed in said casing with clearance, said projectile having a large length/diameter ratio and a center of gravity between its ends; a gas-generating propellant charge in said casing at least partly surrounding said projectile; and an elongated drive body form-fittingly engaging said projectile and disposed at least in part forwardly of said center of gravity in the direction of propulsion of said projectile, said drive body being formed with: a plurality of segments mutually contacting at angularly spaced confronting contact surfaces at which said segments separate upon emergence of the projectile from the barrel of said weapon, a forwardly concave air-encountering surface formed by said segments and defined between a leading outer edge spaced radially from the periphery of said projectile and a trailing inner edge proximal to said periphery of said projectile and rearwardly of said outer edge, an outer periphery of said body formed by said segments having a diameter substantially equal to the caliber of said barrel and engaged by said forward end of said casing, at least one sealing member bridging the mutually confronting contacting surfaces and converging rearwardly toward the projectile away from said outer periphery, and a continuous pressure-receiving surface extending rearwardly from said outer periphery of said body at a circular outer edge thereof to an inner edge proximal to the periphery of said projectile and axially rearwardly of said outer edge of said body, said pressure-receiving surface being of progressively decreasing diameter rearwardly and defining a space with said casing receiving a portion of said charge, said pressure-receiving surface being outwardly concave and curved at least in the region of said outer periphery of said body, the rate of decrease of said diameter being greatest in the region of said outer edge.