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The 14.5×114 mm (.57 Cal) is a heavy machine gun and anti-materiel rifle cartridge used by the Soviet Union, the former Warsaw Pact, modern Russia, and other countries. It was originally developed for the PTRS and PTRD anti-tank rifles, but was later used as the basis for the KPV heavy machine gun that formed the basis of the ZPU series anti-aircraft guns that is also the main armament of the BTR series of armoured personnel carriers from the BTR-60 to the BTR-80. ==Cartridge dimensions== The 14.5×114 mm has 42.53 ml (655 grains H2O) cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions. 400px 14.5×114 mm maximum cartridge dimensions. All dimensions in millimeters (mm). Americans would define the shoulder angle at alpha/2 ≈ 22.50 degrees. The common rifling twist rate for this cartridge is 455 mm (1 in 17.91 in), 8 grooves, Ø lands = 14.50 mm, Ø grooves = 14.95 mm. According to the official guidelines the 14.5×114 case can handle up to 360 MPa (52,213 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「14.5×114mm」の詳細全文を読む スポンサード リンク
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