Quote:
Originally Posted by otasan56
Well I don't understand just why these power factors are used in USPSA and IDPA. Pin shooting power factors are what it takes to move a bowling pin back three feet. PF 210 is where you start with pin shooting.
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A small history lesson then for those who don't know.
Power factors were developed by Jeff Cooper at Gunsite when IPSC was being developed. Cooper was convinced the
only reliable combat load was a 230 gn .45 projectile at 750 fps or more and wanted to reward shooters who used this load over those that shot 9mm.
He worked out the PF formula (velocity )750 fps) X bullet weight (230 gn) divided by 1000 which equaled 170) and this earned "major" points (5/4/3) on the newly developed IPSC targets A/B/C/D scoring zones (A and B zones both scored 5).
Anyone showing 9mm had to achieve a PF of at least 125 and earns "minor" points on target (5/3/1).
Other shooting sports adopted the PF formula as they developed and set their own minimum levels.