Anyone who has spent any time researching or shopping for a brand new AR-15 has come across the question: Should I buy the 1:9 twist or is the 1:7 better?
At one point every one of us has asked, “What does twist even mean? ” Barrel twist refers to the rifling in the barrel of modern rifles making a full 360-degree rotation in a given length of inches.
For example, a 1:7 twist means the rifling makes one complete rotation for every seven inches of barrel. The first number will indicate how many rotations the bullet will make, the second number will indicate how much barrel length it will take to complete the indicated number of rotations.
Simply stated, barrel twist is rotations per length of the barrel in inches.