The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 28, 2010
Filed:
Sep. 07, 2007
David John Bartoli, Murrieta, CA (US);
David John Bartoli, Murrieta, CA (US);
Other;
Abstract
A rifle having a rifled barrel and a cartridge having a bullet having a diameter, a length, a ballistic coefficient (BC), and a muzzle velocity (V) greater than 1250 ft/sec are related to achieve accuracy at very long range in that the twist of the rifling is substantially equal to: where: Vis the entry speed for the transonic, i.e. 1,250 ft/sec., and Vis Vminus V. A rifle barrel for receiving a bullet has rifling twist according to the relationship. A method uses the relationship to determine the rifling twist for a rifle barrel receiving a known bullet. Another method uses the relationship to design a cartridge for a known barrel rifling. The relationship is particularly applicable for bullets having a high BC, such as 0.325 or greater.