Jay6 Posted December 5, 2007 Share Posted December 5, 2007 Is there a chart anywhere showing what FPS translates into PF, and what the PF's are for each class? Link to comment Share on other sites More sharing options...
AlamoShooter Posted December 5, 2007 Share Posted December 5, 2007 bullet weight times speed divide by 1000 a $2.00 calculator will give you what you want 180 x 1000 will work in your head its 180 pf If you round out you can do most of it in your head Link to comment Share on other sites More sharing options...
RePete Posted December 5, 2007 Share Posted December 5, 2007 Bullet weight x Velocity and sometime divided by 1000. My 40 S&W load. 180gr bullet travelling @ 986.8fps (10 shot average). 180 x 986.8 = 177600 for IDPA or 18o x 986.8 / 1000 = 177.6 for IPSC. You don't need to know anything else, otherthan how to use a calculator. Link to comment Share on other sites More sharing options...
Jay6 Posted December 5, 2007 Author Share Posted December 5, 2007 Bullet weight x Velocity and sometime divided by 1000.My 40 S&W load. 180gr bullet travelling @ 986.8fps (10 shot average). 180 x 986.8 = 177600 for IDPA or 18o x 986.8 / 1000 = 177.6 for IPSC. You don't need to know anything else, otherthan how to use a calculator. Thanks guys! Link to comment Share on other sites More sharing options...
LPatterson Posted December 6, 2007 Share Posted December 6, 2007 PF 125 = Minor PF 165 = Major Link to comment Share on other sites More sharing options...
Mark K Posted December 6, 2007 Share Posted December 6, 2007 To work it the other way: You know the power factor you need, you know the weight of the bullet you are using, you need to know the FPS you have to attain: Bullet weight 115 Power Factor 125 Power Factor times 1000 divided by bullet weight 125 times 1000 = 125000 divided by 115 equals 1086.956 fps Bullet weight 200 Power Factor 165 165 times 1000 = 165000 divided by 200 equals 825 fps Mark Link to comment Share on other sites More sharing options...
1911nm Posted December 10, 2007 Share Posted December 10, 2007 Just so one doesn't get confused rounding numbers off, IIRC USPSA does not utilize fractions of a power factor, therefore, don't round off your number, just lop off everything left of the decimal point. Link to comment Share on other sites More sharing options...
RePete Posted December 11, 2007 Share Posted December 11, 2007 Just so one doesn't get confused rounding numbers off, IIRC USPSA does not utilize fractions of a power factor, therefore, don't round off your number, just lop off everything left of the decimal point. As I said, IDPA doesn't but IPSC does. Link to comment Share on other sites More sharing options...
1911nm Posted December 11, 2007 Share Posted December 11, 2007 USPSA website, Rules Manual, appendix C2: 35. Power factor is calculated using the bullet weight and the average velocity of the three rounds fired, according to the following formula: Power Factor = bullet weight (grains) x average velocity (feet per second) / 1000 The final result will ignore all decimal places (e.g. for USPSA purposes, a result of 124.9999 is not 125). Link to comment Share on other sites More sharing options...
RePete Posted December 12, 2007 Share Posted December 12, 2007 USPSA have modded the rules for themselves and doesn't apply to the rest of the world. Link to comment Share on other sites More sharing options...
1911nm Posted December 14, 2007 Share Posted December 14, 2007 USPSA have modded the rules for themselves and doesn't apply to the rest of the world. oops, my bad, one of these days I will learn to read. Link to comment Share on other sites More sharing options...
RePete Posted December 14, 2007 Share Posted December 14, 2007 USPSA have modded the rules for themselves and doesn't apply to the rest of the world. oops, my bad, one of these days I will learn to read. No sweat, it happens! Link to comment Share on other sites More sharing options...
dlp40cal Posted December 19, 2007 Share Posted December 19, 2007 bullet weight -divided by 165000 wil give you bottom of the floor #. say 180- 165000 =917fps so you need go to 930 to940 to pass most grafs. Link to comment Share on other sites More sharing options...
MasterLefty Posted December 19, 2007 Share Posted December 19, 2007 Everyone has given you the formula, but it you want to see it in a visual format pf_cross_reference.pdf Kenny Link to comment Share on other sites More sharing options...
Mapzter Posted December 19, 2007 Share Posted December 19, 2007 USPSA have modded the rules for themselves and doesn't apply to the rest of the world. Actually, that rule is the the same in the international IPSC rulebook: 5.6.3.4 Power factor is calculated using the bullet weight and the average velocity of the 3 rounds fired,according to the following formula: Power Factor = bullet weight (grains) x average velocity (feet per second) / 1000 The final result will ignore all decimal places (e.g. for IPSC purposes, a result of 124.9999 is not 125). Link to comment Share on other sites More sharing options...
1911nm Posted December 19, 2007 Share Posted December 19, 2007 Very cool spreadsheet on the .pdf and will be posted above my reloader (whenever I get the bench made), but where is my 230gr? Link to comment Share on other sites More sharing options...
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