LB,what is the minimum SD that should be used for big game?
I would question why you're trying to achieve the minimum - "just how crappy a terminal performance can we get away with here?"
Weight retention also plays into it - weight that doesn't stick with the bullet doesn't count.
Weight that “doesn't stick with the bullet” counts until it doesn’t stick. Hence bullet construction plays a huge part in determining the effect a bullt has.
For stopping rifles for any sort of bear, I'd like to see SD=0.3 (mathematically illiterate grains/D/D/7000 method) and 90%+ weight retention across the full range of intended impact velocities. So in ..308 a 200gr Weldcore, Northfork, etc.
So a 300g .458” bullet, S.D. .204, is woefully inadequate as a bear stopper? Are you nuts?
I would say the minimum for elk is SD=0.27 and typical weight retention of 70%+ across the full range of intended impact velocities. So in .308, a 180gr Partition, Hawk, Accubond etc.
I killed a 6x6 bull elk with a 350g/.458” North Fork at 211 lasered yards. S.D. was .238. Another with a 150g BT/.308”, S.D. .225. Neither took a step. Think they would have walked away if they knew how low the S.D. values were?
For mule deer I'd say SD=0.22/70% retention. So in .308 a 150gr partition.
For whitetail, antelope etc. any big game bullet is probably fine.
So a small mule deer rates a higher S.D. than a large whitetail?
BTW, the formula for S.D. is NOT “grains/D/D/7000”. Are you “mathematically illiterate”?
