 Americans would define the shoulder angle at alpha/2 ≈ 14.53 degrees.The common rifling twist rate for this cartridge is 305 mm (1 in 12 in), 6 grooves, Ø lands = 9.30 mm, Ø grooves = 9.55 mm, land width = 2.92 mm and the primer type is large rifle magnum.The .375 Hölderlin has 5.65 ml (87 grains) H2O cartridge case capacity.