The tool assists competitors in the United States Practical Shooting Association (USPSA) to determine the “power factor” of their ammunition. Power factor is a numerical value derived from multiplying the bullet weight (in grains) by its velocity (in feet per second), then dividing the result by 1000. The outcome of this calculation is essential for classifying a shooter’s firearm and ammunition combination within USPSA’s competitive divisions.
Accurate determination of this value is important because it directly affects a competitor’s scoring. USPSA categorizes firearms based on power factor, specifically into “Major” or “Minor” categories. Achieving a minimum power factor for the “Major” category typically awards more points for hits within certain scoring zones on targets. Historical context highlights the evolution of power factor as a means to standardize scoring and promote fair competition across varying firearm calibers.