I read through a whole bunch of this thread but not all. If what you choose to read below has been already been covered, my apologies. These are my thoughts.
The old time minimum required energy numbers, killing power calculations, and the like, are a largely useless pool of numbers. Folks want so badly to be able to quantify the killing power of a bullet or cartridge, but it's just not possible. If you like to look at those numbers to compare cartridges, that's cool, but using them as a guideline for killing game is useless. Like some have mentioned in this thread already, shot placement is, in my opinion the most important consideration followed by bullet performance on flesh.
The evolution of modern metallic cartridges, bullet design, etc., is slow... especially in the hunting world. Rifle bullets are rifle bullets. We have small design changes here and there to increase drag resistance, but the bullets are the same. Cartridges are in the same boat. We take some body taper out of a case here and change a shoulder angle there, apply some marketing and we have the next "gotta have" cartridge.
I have to laugh when I hear things like "Energy is Irrelevant" and "Only Impact Velocity Matters." That's similar to saying only horsepower matters to a drag racer, or a truck driver, or anyone for that matter, and we can forget about torque.
Those are outrageous claims looking to illicit an emotional response from people. We see it on social media.... We saw it in this thread. Mission accomplished.
Minimum impact velocities exist because of how the bullets are designed. When you have a single slug that can be shot out of different cartridges producing a wide range of velocities from, let's say 2,000 FPS to 4,000 FPS, which then could translate to impact velocities on flesh just slightly slower than these numbers, compromises must be made. Basically, it's impossible to build a bullet to provide ideal terminal ballistics from its peak velocity to 0. Most manufacturers have designed their supersonic hunting bullets to perform with adequate terminal effect, north of 1700 - 1800 FPS. Those of us who have hunted a lot and killed a lot of animals with different bullets through different cartridges at different speeds can attest to how speed effects bullet performance, and more importantly how unpredictable bullet performance can be.
That leads us to these claims like I mentioned above, that insinuate we only need to worry about one thing like velocity, specifically impact velocity. Well, again this doesn't paint the whole picture. Impact velocity is nothing without mass.... and energy is the byproduct of mass and velocity. Saying one is more important than the other, or one is completely irrelevant, is, once again, click bait and bad information. We need velocity and mass (KE = 0.5 × m × v²) to ensure penetration. Bow hunters understand this. Take a 40 grain arrow at 300 FPS and go shoot an elk or bear and see what happens. Bump the arrow weight up to 400 grains at the same velocity and you have something (theoretical numbers). We need perfect shot placement to poke holes in vitals, and the icing on the cake is a bullet that works as designed to disrupt tissue, fluid and a larger vital zone. We expect optimal bullet performance everytime, but that is not always the case. If you have good shot placement, you will still have an ethical kill no matter what the bullet does. I've personally seen this many times and I'm sure many of you have as well.
Velocity alone guarantees nothing. It doesn't guarantee your bullet will open up into a perfect petal with 100% weight retention, it doesn't guarantee a pass through, it doesn't guarantee penetration through dense muscle and bone. Most of us have experienced bullet failures of some sort on game. Impact on flesh results in a 100% unpredictable outcome every time. That is a fact. Lab conditions simply don't exist in the field and the variables change every time. Numbers are nothing more that a comparative tool in this game, impact on living tissue in **field conditions** is not quantifiable.
Cheers.
memtb
