ksshooter Posted November 9, 2004 Share Posted November 9, 2004 Ok I got my Chrony now and I can finally chronography some loads. I am trying to figure out a format to make on my computer that allows me to make this easier. What does everyone use the most SD, Extreme Spread, or do you just average the velocities. This is all new to me please help me out. I am thinking about plugging all this info into a spreadsheet which will include my drop chart. Link to comment Share on other sites More sharing options...
ErikW Posted November 9, 2004 Share Posted November 9, 2004 Chasing statistic variables is a fool's errand. Here are some relevant topics on chronographing... http://www.brianenos.com/forums/index.php?showtopic=14694 http://www.brianenos.com/forums/index.php?showtopic=14601 http://www.brianenos.com/forums/index.php?showtopic=14422 Link to comment Share on other sites More sharing options...
.40AET Posted November 9, 2004 Share Posted November 9, 2004 Most importantly, make sure that nothing falls below the PF that you are required to make at a match. Nervously sweating it out at the chrono sucks sh*t. Erik has all of the good stuff to read in the search results listed. Link to comment Share on other sites More sharing options...
JohnRodriguez Posted November 10, 2004 Share Posted November 10, 2004 First thing you need to do with your new crony is to take it out, aim for a non vital part and shoot a hole in it. Might as well get it over with sooner than later. I made a couple of speedsheets for working out different loadsl. Make one that has the Date, Bullet caliber, weight, and the a area where you can write down the Velocities of each shoot for the respective powder charge. I like to work in 0.5 gr increments. Make a who bunch of blank copies, put them in a binder, and don't ever throw them away, keep them to review them in the future. I don't trust computers enough to not keep a writen backup. On you second spreed sheet make a table of all your data, with all the bad info take out, include the bullet make, weight, type, power brand, powerder charge, PF, velocity average. make one upto date copy, put it in a clear cover and hang it by your reloader so you can have instant access. Link to comment Share on other sites More sharing options...
lynn jones Posted November 10, 2004 Share Posted November 10, 2004 remember to shoot over the chrony! Link to comment Share on other sites More sharing options...
shred Posted November 10, 2004 Share Posted November 10, 2004 My chrono spreadsheet looks sorta like this on each line (one line per load) Bullet Weight, Type/MFG, Powder Type, charge weight, OAL, average velocity, average PF, gun, date, temperature, place/chrono, comments and then the actual velocities (usually 10 or so). The average velocity and PF calculate off the actual velocities. With those I can compute SD or KE or whatever should I so desire later. Link to comment Share on other sites More sharing options...
DogmaDog Posted November 10, 2004 Share Posted November 10, 2004 I tooled around for a while with some numbers, and figured out that everyone pretty much has the right answer: Load your ammo so that it averages 5 pf more than the pf floor you are aiming for. I have an Excel spreadsheet and a derived table that shows average, min, max, standard D, and sample size for both pf and velocity. I plot the results of my testing in a graph, and fit a linear function to the data, in order to predict what charge I need to make 170 pf. I also weigh several bullets, and figure out the lower bound of a 90% confidence interval on the average weight--that's what I use to calculate power factors from then on with that bullet. Dogmadog Link to comment Share on other sites More sharing options...
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