Rifling is often described by its twist rate, which indicates the distance the rifling takes to complete one full revolution, such as “1 turn in 10 inches” (1:10 inches), or “1 turn in 254 mm” (1:254 mm). A shorter distance indicates a “faster” twist, meaning that for a given velocity the projectile will be rotating at a higher spin rate.
Button Rifling and Cut Rifling machines are for smaller calibers from 0.22 to 50 BMG. Broach Rifling Machines are for larger artillery barrels.
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