Explore: Rifling Twist

creating such grooves. The opposite of rifling is smoothbore. Rifling is measured in twist rate, the distance the rifling takes to complete one full revolution

would define the shoulder angle at alpha/2 = 23 degrees. The common rifling twist rate for this cartridge is 305 mm (1 in 12 in), 6 grooves, Ø lands =

Americans define the shoulder angle at alpha/2 ≈ 20 degrees. The common rifling twist rate for this cartridge is 254 mm (1 in 10 in), 6 grooves, Ø lands =

6 mm or 64 calibers) rifling twist rate to the more common four grooves, right-hand 1:12-inch (1:304.8 mm or 54.8 calibers) twist. This was done as the

sizes in millimeters (mm) The rifling twist rate for this cartridge is 177.8 mm (1 in 7 in), 6 grooves right hand twist, Ø lands = 5.56 millimetres (0

shooting. Heavier bullets perform best in rifles that have an appropriate rifling twist rate taking into consideration the diameter, length, and other physical

would define the shoulder angle at alpha/2 ≈ 20.42 degrees. The common rifling twist rate for this cartridge is 220 mm (1 in 8.66 in), 4 grooves, Ø lands

would define the shoulder angle at alpha/2 ≈ 22.2 degrees. The common rifling twist rate for this cartridge is 280 mm (1 in 11.02 in); although 250 mm (1

Americans define the shoulder angle at alpha/2 ≈ 35 degrees. The common rifling twist rate for this cartridge is 1:228.6 mm (1:9 in), 8 grooves, Ø lands =

CIP cartridge dimensions, all sizes in millimeters (mm) The common rifling twist rate for this cartridge is 275 mm (1 in 10.83 in), 4 grooves, ø lands