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Wind drift is figured at 12 MPH & 90° angle. Federal uses a 24" BBL & a .315 Ballistic Coefficient for their cartridge in .243 Win caliber, I use Sierra's 2700 fps & above low .282 BC and a 25" BBL for 3500 fps MV for my 243/06 Wildcat. This makes it a 300 yard maximum deer bullet to achieve +1000 ft/lbs of energy. It will also ricochet when hunting fox & coyotes on frozen ground, which in my opinion, makes it unsafe for that type of hunting. Lead is always in feet! The 243/06 Wildcat has the retained energy to be a 600 yard coyote cartridge, with the 100, 95, 87, or 85 grain high Ballistic Coefficient bullets. The 85 grain is the lightest bullet I use in my 243/06 Wildcat cartridge, it is a fantastic long range coyote rifle with any of the above bullet weights! At present I'm using 59.5 grains H-4831sc and Federal 215 primers and a little more powder. Will try N-560 powder, I saw a published load of 63.1 grains of N-560 powder used with an 85 grain Barnes XST with MV velocity of 3,732 fps with a 26" barrel. I was using my 243/06 Wildcat rifle with a Weaver K 6 scope (a K4 is better for running shots) and hopefully, Sierra 100 grain Boat Tail .430 B.C. bullets, now with 59 grains of IMR 7828 and Fed. 215 mag primers. I don't know what mv I was getting. Trajectory was figured at 3593
fps
and a ballistic coefficient of .415, which is the B.C. that the
trajectory shows when using Federal's Sierra 85 grain HPBT bullets in
their .243 loads. Just checked my velocity with this bullet, averaged
around 3350 fps that's
243 fps less, guess I need to increase the load until there are signs
of pressure. Federal claims the 243 Win will do 3320 fps in a 24'
barrel.
My 243 Win load was only showing around 3100 fps in a 22" barrel, that
is 250 fps less than my 243/06 mild Wildcat load with the same 85 grain
Sierra bullet. Sectional
density is the same irrespective of bullet shape, here is a list of 6mm
SD's: 70-gr .169; 75 .181; 80 .194; 87 .210; 90 .218; 95 .230; 100
.242. Here's the
SD equation: SD is the ratio of bullet weight to the square if the
bullets
diameter. The 6mm 55 grain Nosler bullet
(
.133-SD) has a higher BC than the 55 grain
bullet .224 bullet which
has a higher .157-SD; 60-gr is .171-SD. Otherwise, it's my 243/06
wildcat 95% of the time on coyotes, with the 87 grain V-Max bullet, SD
.210, BC .400.
Rick Jamison says, an SD of .140 is the minimum for coyotes, an a lower limit of .210-SD for deer! A 150-gr .308-Cal, SD is .225; 165-gr has a .248-SD. Whisky Chamberlain of Idaho took
15
consecutive big bull elk, all one shot kills, with a regular .243
Winchester. Proper range and bullet placement are the key factors. A
6mm-06 Wildcat should be efective using a Nosler partition or Remington
100 grain Core-Lokt Ultra bullet, they take elk and moose with a
bow! This 6mm
Sierra 85 grain HPBT bullet was
rated
as a number one quick kill whitetail deer -- cartridge bullet
combination! However, it is NOT my favorite 6mm .243 Win
or 243/06 deer bullet & load. Wind drift: A 45-degree wind drift angle isn't half the wind drift of a 90º-angle, but is three-quarters the drift. It has a 70 to 75 percent effect, even though the angle is only halfway between no drift effect and full drift effect. The drift effect is not proportional, due to the aerodynamic ballistics of a bullet in flight. Just remember that halfway between full and zero effect is nearly three-quarters the drift of 90-degrees. Memorize these aerodynamic ballistic realities. Related Pageshttp://www.udarrell.com/leadingrunninggamerifle.html http://www.udarrell.com/ultimate_deer_cartridge.htm http://www.udarrell.com/wisconsin_coyote_hunting.html A Page full of my links The Real Political Issues and People Empowerment Posted:
12/09/00; Edited:02/15/07 |