Ballistic Coefficent for Steve Brooks Creedmore
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Ballistic Coefficent for Steve Brooks Creedmore
, Ok I seem to have lots of questions today, but this is the last one, I promise. I need to know the Ballistic Coefficent for Steve Brooks Creedmore design bullet (.45 caliber, actually .458, cast 30/1, weighs 545 grains, top two driving bands are slightly undersized in order to seat into or near rifling). When I have this figure I can plug it into a long range ballistic program to get some fairly close sight settings (maybe).
Everything I know about BPRC I have forgotten at least three times, Now I write it down. Have you seen my note book?
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Jerry: BCs of BPCR bullets is a very in-exact science. The shape of bullets traveling this slow has very little to do with their BCs and the number of driving bands and grease grooves can also exert an influence. I once did a test with Dr. Oehler who makes the chronographs where we tested BCs of BPCR bullets at a full 200 yards measured to the tenth of an inch. This was done with one of his Personal Ballistic Laboratory Systems. I might also add that Dr. Oehler has designed and built much of the instrumentation used at Government Proving Grounds.
The closest bullet we used to a Brooks Creedmoor was Lyman's Postell weighing 536 grains. It had a BC of .402. Next to it was Redding SAECO's #745 weighing 533 grains and its BC was .399. My guess is that if you give your bullet a value of .410 you would be very close. And that's about the best I can do to help.
The closest bullet we used to a Brooks Creedmoor was Lyman's Postell weighing 536 grains. It had a BC of .402. Next to it was Redding SAECO's #745 weighing 533 grains and its BC was .399. My guess is that if you give your bullet a value of .410 you would be very close. And that's about the best I can do to help.