Home Forums Hunting & Shooting Ask The Gunwriters energy vs. damage vs. caliber

ok, gonna try to get my thoughts out coherently.

with the advent of advanced bullet designs like the barnes, i keep hearing that they can "make a .223 into a .243, and a .243 into a .270."

well how does that translate into hunting? i mean, does that mean a .25-06 is now a grizzly gun? seems like it isn't no matter what bullet.

however, is it the damage caused or is it the energy transfer that makes the difference? on non-dangerous game it seems like it wouldn't matter, as 30" of penetration from a .243 would go a long way toward killing.

but- let's say a charging grizzly or wounded african game- huge penetration doesn't buy you anything in the way of peace of mind since energy is what's needed to slap them down and end the danger. right? that bullet could go all the way through and yet if that animal is not stopped, it will die from a bullet hole but only after chewing on you a while.

That's a lot closer to the truth than a lot of guys on here are going to admit.

Contrary to popular belief, energy won't "slap them down"
Broken parts, broken bones, cns damage is what stops..........

Lewis and Clark found grizzlies difficult to kill:

This proved to be a false sense of security. On May 5th a grizzly was encountered which did not run away. Clark described it as a

�verry large and a turrible looking animal, which we found verry hard to kill we Shot ten Balls into him before we killed him, & 5 of those Balls through his lights.�

Lewis wrote that after the bear had been shot,

�he swam more than half the distance across the river to a sandbar & it was at least twenty minutes before he died; he did not attempt to attack, but fled and made the most tremendous roaring from the moment he was shot.�


Just me, but a .243 will kill a grizzly fine. A charging grizzly is still going to be pissed off, and a .338 or a .243 will likely not put it down immediately. I've also seen grizzlies killed by traditional bow and arrow (not even compound bow, I'm talking longbow).

Also of note, USMC snipers in Iraq used 50 cals from fixed positions defending the base. They used 50 cals because .308s weren't enough to put a drugged up suicide bomber down. That's a human, definitely not difficult to kill unless drugged and amped up.

It's not energy, or velocity, or size of bullet, etc. etc. A bullet, or arrow, or rock, or whatever, that puts a hole through heart and lungs will kill the object.

right, so what i'm asking is does that mean if i shot a .243 all the way through a cape buff with a wonder bullet of some sort...the energy isn't needed to make sure i don't expire WITH him?

seems a lot like comparing a bow and arrow to a rifle. that bow needs zero energy as long as it zips through the target. however, even a little doe keeps running with all that damage...

just asking an honest question here, not to ruffle any feathers. i have zero experience with this stuff, as i primarily hunt in ohio.


i see a distinction here and wanted to see what you guys thought.

your point is on both sides of the fence. a 308 should have been enough if, as you said, holes kill, not energy. a 50 cal energy made the difference, since it can make a hole too.

The lethality of energy is only in play when it's measured in terms of actual damage done.

A 9mm with +P ammo delivers approx 450-500 ft/lbs of energy at the muzzle. So does a kick from a female MMA fighter. Other MMA fighters absorb that energy with no problem. If you shot them with a 9mm on the other hand, they'd quickly die.

Stopping power is a myth when you're talking energy. Stopping power is fact when you figure that energy into actual damage done.

Shock is not damage. Torn blood vessels, ripped lungs, ruptured heart, broken spine. That's damage.

A 243 that tears the same amount of tissue in the same area as a 450 Marlin is going to have the same stopping power.

What's often overlooked is physical conditioning and mental fortitude of a given critter. Some deer or bear as it may be in this OP, are in better shape than others. They store and process oxygen better, etc. Hit them in the heart, there is still a good chunk of oxygen in the brain. He will last longer than another bear with less oxygen in the brain.

Mental fortitude is a factor as well as all creatures are given the fight or flight reflex. Some will fight, while others will flight.

Stopping power? No such thing.
Damage (or trauma)? It's everything!

Not a gun-writer and all my experience has been on NA game mostly caribou and a few moose. I have also shot a lot of wet newsprint. lots of folks dismiss energy as a measure of killing power. In my mind energy is a very useful number..it is a scientific measure of how much work the projectile will do.

The projectile will determine how that energy will be put into action. A semi frangible 6.5 120 grain Sierra at 2800ft pounds will create a wide wound about 1 foot deep. A hardcast 450 grain .458 bullet at 2800 ft-pounds will create a long narrow wound about 4-5 feet deep. Total wound volume will be similar and energy will be the closest mathematical measure of the wound volume.

It won't be perfect and I'd bet the 458 bullet would create a bit more wound volume but not nearly as great a difference as some folks might think and that some other killing power mathematics might lead you to believe.

In any case if shooting a charging Grizzly I'd want something that could take out his brain. The Hardcast bullet at low velocity looks good. For a caribou through the lungs I guarantee the 6.5 will kill faster than the 45-70 with hardcasts.
I know because I have done it.

You can change the equation a bit in the above example by changing bullet types. For example using a 120 Grain TSX in 6.5 and a 350 grain semi-frangible bullet in 458 might equal up the wounding action a bit.

The advantage of a big bore is that all other things being equal the larger bore can send more energy downrange.

Hope this makes some sense.

Energy is required to drive a bullet home, but the bullet must be up to the task. Broken body parts is what kills stuff. Reallistically can't have one without the other especcially when talking tough to kill animals like those that want to hunt you back!

Bonded bullets, Barnes, Partitions, etc will allow you to do more with less but I'd not be taking a 25-06 on a Griz hunt!

Though complete penetration on deer for example is not required to kill it, I won't be convinced it's not a good thing to have...

Speed kills without a doubt, but there is a tradeoff. Since someone brought up Cape Buffalo, in my opinions a 500gr/45 cal bullet @ 2500 plus fps(of proper construction like a TSX) will leave a significant, more telling instruction that same bullet driven at 2150. In the 30 cal world where I have a bit more experience, given the same parameters, a 180gr bullet3200 plus leaves a much more dramatic impression than the same bullet @2700.

this

What matters is location and wound channel. 'Energy transfer' per se is not a factor. First I would suggest thinking of energy (kinetic energy specifically in this case) as simply being a function of mass and velocity. It is not some sort of 'separate' physical attribute. As velocity is squared in the kinetic energy formula, it becomes relatively more important than mass. Thus a very high velocity 6mm bullet could well have more kinetic energy than a larger caliber, heavier, but slower bullet.

True that in the case of charging dangerous game, the larger heavier, but slower, projectiles can be favoured. However, that is in part due to the fact that the shot is likely to be short range. Smaller caliber, higher velocity projectiles have the advantage in retaining sufficient velocity at range to ensure proper bullet performance (i.e. opening). However, whatever the particular combination being considered, it is location and wound channel that is going to matter. A leg hit is going to be about equally ineffective, although perhaps more 'dramatic' with a .50 BMG than a .243.

+ 1000

Agree 100%.

That's the problem. Energy is a measure of how much work the bullet CAN do on an animal, not how much it will do. The bullet's kinetic energy is converted into many forms between leaving the muzzle and coming to rest in an animal, only one of which is the mechanical damage done to the animal's tissue.

I predict an energetic thread.

You make a good point.

The 50 cals were used because the marine snipers used them to conveniently separate insurgent brains from operating their bodies, normally dropping them on the spot. I believe the base also used the heavy 50 cals because trajectory wasn't much of an issue, and the positions were fixed instead of mobile. The pictures were...interesting.

At some point a large enough projectile, with enough energy, would do the same thing to a grizzly. I would guess the weapon would be larger than I wanted to carry. But your point is correct. At some level of energy, a larger projectile will do more damage than a smaller projectile.

As an interesting side note, I killed an interior grizz in Alaska several years ago. My guide backed me up with a 7mm Wby Mag. Carry on.

Wrong. It's the disconnecting of vitals resulting in loss of blood pressure. This can be accomplished with a bow/arrow where energy is of no consequence.

Bullet placement, bullet placement, bullet placement.

Got my vote on the 7 Wby.