8x68s...https://en.wikipedia.org/wiki/8%C3%9768mm_S
9.3x64...https://en.wikipedia.org/wiki/9.3%C3%9764mm_Brenneke
6.5x57R...https://en.wikipedia.org/wiki/6.5%C3%9757mm_Mauser
The 9.3/375 Flanged is my wildcat necking down the .375 Flanged Magnum
The
.375 Flanged Magnum (9.5×75mmR), also known as the
.375 H&H Flanged Magnum is the companion cartridge to the .375 H&H Magnum for use in double rifles and was released together with the .375 H&H Magnum by Holland & Holland. It is a rimmed (flanged) cartridge and is loaded to a lower pressure level of 47,000 psi (320 MPa).
View attachment 573085
The CIP has published mandatory specifications for the .375 Flanged Magnum. Bore ∅ for the cartridge is 9.30 mm (0.366 in) and the groove ∅ is 9.55 mm (0.376 in). The barrel will have six grooves with a twist of one revolution in 305 mm (12.0 in) and each groove being 2.92 mm (0.115 in)wide. SAAMI has not published specifications nor recommendations in regard to this cartridge.
The cartridge is capable of firing a 235 gr (15.2 g) bullet at 2,800 ft/s (850 m/s), a 270 gr (17 g) bullet at 2,650 ft/s (810 m/s) and a 300 gr (19 g) bullet at 2,500 ft/s (760 m/s) with muzzle energies of 4,090 ft⋅lbf (5,550 J),4,200 ft⋅lbf (5,700 J) and 4,160 ft⋅lbf (5,640 J) respectively. The cartridge is appropriate for the same game species as the .375 H&H Magnum cartridge.