The .303 British has 3.64 ml (56 grains H₂O) cartridge case capacity.
The pronounced tapering exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under challenging conditions.

.303 British maximum C.I.P. cartridge dimensions.
All sizes in millimeters (mm).

Americans would define the shoulder angle at alpha/2 ≈ 17 degrees.
The common rifling twist rate for this cartridge is 254 mm (10.0 in) 10 in), 5 grooves, Ø lands = 7.70 millimetres (0.303 in), Ø grooves = 7.92 millimetres (0.312 in), land width = 2.12 millimetres (0.083 in) and the primer type is Berdan or Boxer (in large rifle size).

According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the .303 British can handle up to 365.00 MPa (52,939 psi) Pₘₐₓ 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.

This means that .303 British chambered arms in C.I.P. regulated countries are currently (2014) proof tested at 456.00 MPa (66,137 psi) PE piezo pressure.

The SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) Maximum Average Pressure (MAP) for this cartridge is 49,000 psi (337.84 MPa) piezo pressure (45,000 CUP).

The measurement .303-inch (7.70 mm) is the nominal size of the bore measured between the lands which follows the older black powder nomenclature.
Measured between the grooves, the nominal size of the bore is .311-inch (7.90 mm).
Bores for many .303 military surplus rifles are often found ranging from around .309-inch (7.85 mm) up to .318-inch (8.08 mm).
Recommended bullet diameter for standard .303 British cartridges is .312-inch (7.92 mm).
The .303 British has 3.64 ml (56 grains H₂O) cartridge case capacity. The pronounced tapering exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under challenging conditions.
.303 British maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).
Americans would define the shoulder angle at alpha/2 ≈ 17 degrees. The common rifling twist rate for this cartridge is 254 mm (10.0 in) 10 in), 5 grooves, Ø lands = 7.70 millimetres (0.303 in), Ø grooves = 7.92 millimetres (0.312 in), land width = 2.12 millimetres (0.083 in) and the primer type is Berdan or Boxer (in large rifle size).
According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the .303 British can handle up to 365.00 MPa (52,939 psi) Pₘₐₓ 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.
This means that .303 British chambered arms in C.I.P. regulated countries are currently (2014) proof tested at 456.00 MPa (66,137 psi) PE piezo pressure.
The SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) Maximum Average Pressure (MAP) for this cartridge is 49,000 psi (337.84 MPa) piezo pressure (45,000 CUP).
The measurement .303-inch (7.70 mm) is the nominal size of the bore measured between the lands which follows the older black powder nomenclature. Measured between the grooves, the nominal size of the bore is .311-inch (7.90 mm). Bores for many .303 military surplus rifles are often found ranging from around .309-inch (7.85 mm) up to .318-inch (8.08 mm). Recommended bullet diameter for standard .303 British cartridges is .312-inch (7.92 mm).
.303 British