"How'd you get to 60%?"
When I was CEO of Cast Performance several years ago we did a LOT of tests of our bullets and compared them to every other bullet we could, in penetration and cavitation. I have found that expanding bullet that retain 60% or more of their weight will nearly always give full penetration in large deer and elk too. It's not gospel, but it's a good rule of thumb.
You'll see I wrote 60%--------meaning AT LEAST 60%.
When shooting machined expanding solids in a 223 that weight 65 grains I found that in our ballistic test trough shooting into media and real bones that a 223 will out penetrate many 30 caliber 150 and 165 grain bullets that come apart. Notably the Sierras and some of the Speers. The "wound channels" are narrower, but far easier to control. Very few deviate from the direction of impact more then about 10 degrees. With fragmenting 30 cals it was common to get wide wounds, but the bullets can and often do turn as much as 30 degrees. On rare occasion I have seen them turn over 60 degrees.
A poor bullet that hits the heart or both lungs is still devastating most times. And hunters that are good marksmen do well with them most times, because they place them right. But a bullet that holds together also does well. Many times the "electric-kill" you see with the poor bullets is not quite as dramatic with a bullet that doesn't break up, but you don't loose game hit with them in the right place either. And they give you exits nearly every time if you are not pushing the edge of the envelope too hard. (as an example, shooting elk with a good .224 bullet is not likely to get many exists either, but 120 grain 25 calibers often do)
The positive point to a bullet that holds together is when the angles are not perfect and you need to break a bone on the close side of a deer, elk, moose bear or whatever. Burgers and many Sierras, as well as many Speer bullets break up on bone (even light bone like a rib) and not penetrate well, and very often don't penetrate straight.
This is my reason for my own preference in bullets.
I want exits, every time. I admit I don't always get them, but I do most of the time.
I want to be able to make the exit right where I want it, or to be or at lease very close to where I want it. Good bullets do this for me.
The fragmenting explosive bullet do kill very fast if you get them into the area of the chest you want them to be. But they don't always cooperate, and I have seen this so many times as a hunter and as a guide that I just don't take the chance much anymore.
60% + seems to be a good rule of thumb to follow.
Some "plain vanilla" bullets hold 60% or more a rule, so you need not always spend big money of a very good bullet. Many of the Remington Core-Lokts do very well (especially the older ones) and the Winchester Power Points seem to think they are Nosler Partition in many cases.
So it's not a matter of expense. Just paying attention to the jacket taper and thickness is a good way to start. Bonded core bullets are very good as a rule too.
Last edited by szihn; 04/14/18.
