Enter the muzzle velocity (fps) and the barrel twist rate into the Calculator. The calculator will evaluate the Bullet Spin Rate.

## Bullet Spin Rate Formula

BSP = MV*720 / BTR

Variables:

- BSP is the Bullet Spin Rate (RPM)
- MV is the muzzle velocity (fps)
- BTR is the barrel twist rate

To calculate Bullet Spin Rate, divide 720 by the barrel twist rate, then multiply by the muzzle velocity.

## How to Calculate Bullet Spin Rate?

The following steps outline how to calculate the Bullet Spin Rate.

- First, determine the muzzle velocity (fps).
- Next, determine the barrel twist rate.
- Next, gather the formula from above = BSP = MV*720 / BTR.
- Finally, calculate the Bullet Spin Rate.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

muzzle velocity (fps) = 3000

barrel twist rate = 2.5