cecil Posted May 9, 2013 Share Posted May 9, 2013 I just ordered a Pro Chrono Digital... whats the method for calculating POWDER FACTOR ? Link to comment Share on other sites More sharing options...
bishop414 Posted May 9, 2013 Share Posted May 9, 2013 bullet weight (grains) x chrono fps / 1000 = power factor Link to comment Share on other sites More sharing options...
Amerflyer48 Posted May 9, 2013 Share Posted May 9, 2013 bullet weight (grains) x Velocity (fps) / 1000 = PF 230x850/1000 = 195.5 PF 155x1200/1000 = 186 PF Link to comment Share on other sites More sharing options...
02doooce Posted October 20, 2013 Share Posted October 20, 2013 USPSA has a power factor calculator, I usually just set that as a favorite and pull it up every time I chrono at the range Link to comment Share on other sites More sharing options...
Guest Posted October 20, 2013 Share Posted October 20, 2013 Congrats on getting a chrono! In my book it is as important for reloading as a powder scale or digital//dial/vernier caliper. If you are shooting USPSA might want to look at the rule book for the definition (section 5.6) and actual chrono procedure/power factor calculation (appendix C2) so you you can understand what you need to meet at a match and adjust your loads accordingly. http://www.uspsa.org/rules/2010HandgunRulesProof3web.pdf Link to comment Share on other sites More sharing options...
Sean Gaines Posted October 20, 2013 Share Posted October 20, 2013 Congrats on getting a chrono! In my book it is as important for reloading as a powder scale or digital//dial/vernier caliper. If you are shooting USPSA might want to look at the rule book for the definition (section 5.6) and actual chrono procedure/power factor calculation (appendix C2) so you you can understand what you need to meet at a match and adjust your loads accordingly. http://www.uspsa.org/rules/2010HandgunRulesProof3web.pdf +1 Link to comment Share on other sites More sharing options...
GrumpyOne Posted October 20, 2013 Share Posted October 20, 2013 I just ordered a Pro Chrono Digital... whats the method for calculating POWDER FACTOR ? What kind of POWDER are you looking for? Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted October 20, 2013 Share Posted October 20, 2013 whats the method for calculating POWER FACTOR ? If you're shooting a 125 grain bullet at 1,000 fps, your PF is 125. But for competition purposes, you'll find that firing 20 rounds over your new chrono will yield a variation (950 - 1,050 fps, eg). So, you should use the lowest velocity x bullet weight to come up with a 118.75 PF, and bump up your powder charge a bit so that the LOWEST velocity you get is a PF 125. Link to comment Share on other sites More sharing options...
levellinebrad Posted February 18, 2014 Share Posted February 18, 2014 I realize this an older thread but thought I would share my opinion with Hi Power Jack anyway. I try to load all my rounds at 130 PF, That way, if you ever have your rounds chrono'd at a match, your avg velocity should be good to go. This should also make you safe from temperature variances from the day you tested your loads and having them tested at a match. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted February 18, 2014 Share Posted February 18, 2014 I load my rounds at 130 PF, your avg velocity should be good to go & make you safe from temperature variances Level, we're really saying the same thing. If you check 20 of your PF 130 rounds, you'll probably note that NONE of the rounds is below PF 125. But, some are pretty close to 125. And, if you check to see if NONE are below PF 125, you'll probably have a PF of c. 130. But, depending on your powder, PF130 may NOT make you immune to severe temp variances - you might need greater PF. Link to comment Share on other sites More sharing options...
tbrtt1 Posted February 18, 2014 Share Posted February 18, 2014 I load my rounds at 130 PF, your avg velocity should be good to go & make you safe from temperature variances Level, we're really saying the same thing. If you check 20 of your PF 130 rounds, you'll probably note that NONE of the rounds is below PF 125. But, some are pretty close to 125. And, if you check to see if NONE are below PF 125, you'll probably have a PF of c. 130. But, depending on your powder, PF130 may NOT make you immune to severe temp variances - you might need greater PF. Hence the importance of owning or at least having unfettered access to a chrono to be able to test loads in a myriad of conditions if one is competing regularly. Link to comment Share on other sites More sharing options...
CZinZA Posted February 18, 2014 Share Posted February 18, 2014 (edited) If you want to check your margin of safety with your power factor, you can check out my spreadsheet posted in the thread called what's your power factor margin of error. Sorry- not allowed to post the link Edited February 18, 2014 by CZinZA Link to comment Share on other sites More sharing options...
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