RE: knockdown power... fact or myth?
 

I agree CD, a cannon ball would probably be good for "knock-down!"
A 2X4 to the head would be knock-down power too!
But, bullets have already done their jobs, before the deer can think about running!
It is hilarious on TV how when someone gets shot, it picks them straight up, and then throws them backwards!! Only in Hollywood!
In reality, (unless you hit heavy bone) neither the human body, nor deer have the density to provide enough resistance to a speeding bullet, so as to "knock them down." So the animal either drops, or runs.

Now for the next part of the debate, a "complete pass-through" or a bullet that transfers all its energy, and does not exit.
It gets tricky here too! I prefer a complete pass-through, with the RIGHT amount of bullet expansion. Some might argue that this is "wasted energy." Whereas a bullet that has stopped, utilized ALL of it's energy in the animal.
Maybe yes, maybe no. With the wrong bullet, a pass-through can be terrible, no expansion, no blood trail.
On the flip-side the bullet that stopped in the animal, did it expand too quick, and "explode" on contact? Or was it under-powered and did not pass through?
Again, I prefer the complete pass-through, with a GOOD bullet! It delivers just as much as, and in some cases MORE energy, than the bullet that stopped inside the target!

Again, "knock down" is a MYTH, except in bowling and boxing!

RE: knockdown power... fact or myth?
 

In many years of hunting, I have seen bullets exit, stay inside and come apart on impact. Any bullet however that has penetrated into the vitals and beyond has done the job well. As mentioned already, knockdown power is just in the movies. All you need is to get that bullet into or through the vitals. High Shoulder and neck and brain shots oftenAPPEAR to have knocked the beast off its feet but it just don't happen.

RE: knockdown power... fact or myth?
 

I like what one bullet maker asked (I don't remember which one)
"Exactly at what point in the animals death did the bullet fail?"
The only bullet failures that I've seen are some of the Ballistic Tips comming apart on impact, and not reaching the vitals, and I've had two 7MM RM's, that judging from the exit wounds, they did not expand at all!
In all my deer hunting years, I've only recovered 2 bullets, all my others were pass-throughs. The one I really remember is a 165 gr. Nosler Partitioner in .308 Win that lodged between the shoulder and the hide. It was perfectly mushroomed at least twice the original diameter!
I think that most of the bullet "failures" are a result of a poor choice on the shooters part with the wrong bullet/caliber for the situation!

RE: knockdown power... fact or myth?
 

knockdown power... fact or myth?

I guess it all depends on how you define it. However, as portrayed by Hollywood, where a guy catches a shotgun blast and is literally picked up and carried away, is HOGWASH (or something less polite!!) If you subscribe to Newton's Third law of Motion, no projectile can ever deliver a greater blow to the target than is evidenced by the recoil effect in the opposite direction.

For example, some people thinkthat "a .45 ACP bullet will knock a man down regardless of where it strikes him". This too is B.S.! I once watched a demonstration at Fort Bragg NC in which one sergeant fired GI .45 APC Ball ammo at another sergeant's hand who was equipped with a Kevlar "catcher'smitt", with which he was CATCHING THE BULLETS and holding the mitt out palm up so the audience could see the bullet he just caught! Range, about 15 feet. Each time the bullet impacted the mitt, his hand jerked backward some, about the same amount as did the hand of the guy shooting the pistol! I therefore assume the mitt weighed about the same as an M1911A1.

The only time a knockdown occurs is when something is done to the quarry by the effect of the bullet that prevents the critter from continuing what it was doing when hit. This effect generally involves damage to, or at least temporary interuption, of its' nervous system - not necessarily a brain or spine hit, but a shockwave that effects its' nerves in a massive sort of way. For example, I have shot black bears that fell at the shot, then got up and ran a short distance before keeling over, deader than a doornail! Were they "knocked down" by the bullet? Nope, not physically. But the nervous shock of the bullet passing through their chest cavity was sufficient to short-circuit their system for a short period of time. They recovered from this shock, recovered muscular control, got up, and started to run away before the lack of oxygen from the destroyed heart & lungs caused their system to go offline permanently.....

Hollywood aside, I think the myth of "knockdown power" may be promoted by the ballistics tables, which show kinetic energy figures in terms of "foot-pounds of energy". This term is defined as "the number of feet that particular amount of energy will move a 1-pound object if all the energy is expended on the object." Now, who believes that a bullet carrying "3000 foot-pounds of energy" will actually move a 1-pound block of some material that traps the bullet in it3000 feet downrange? Or that a 100-pound object will be moved 30 feet? If you believe this, I have A slightly used bridge in the vicinity of New York City for sale cheap.....

Maybe what we need is a new system for measuring bullet energy. For example, we all admit that a .22 caliber, 55-grain bullet rated at 1500 foot-pounds of energy will do an entirely different job on a woodchuck than will a 400-grain .45/70 bullet carrying the same ft/lb rating.....

One is an elk load, while the other obviously is not!

RE: knockdown power... fact or myth?
 

My only trouble with Ballistic tips also happened with the 7 MM Mag. These were some of the early BT's One did the job but the other only made a big welt. The first one went in behind the shoulder, turned 90 degrees and came out the hind quarter. The other hit ther shoulder and didn't penetrate at all. The Ballistic tips have been improved several times since then and NOW IMO are amoung the best deer bullet out there. One should stay with the heaviest per caliber BT's for game bigger than deer. I also keep them loaded to between 2600-2800 fps.

RE: knockdown power... fact or myth?
 

Just something FYI. I hunted last year with 150gr swift scirocco bonded bullets in my 7mm mag. These bullets will devastate a deer. Imean, pass thru every time with a quarter sized entry and a fist size exit with a behind shoulder shot. They will break both shoulders and still pass also. 50-300 yds, ive made all these shots and they always pass and expand awesome. You guys should try them in your 7mm's. Please try them!:DYou wont believe it.

RE: knockdown power... fact or myth?
 

You have it right except your still thinking about energy transfer. Energy does not kill. You have to stick with tissue damage, and an expanded bullet crates more tissue damage than one that does not expand well, and an expanded bullet that passes through causes even more tissue damage than one that does not, thats all it comes down to, has nothing to do with energy transfer. Not to mention two holes will alow a deer to bleed out faster than one.

RE: knockdown power... fact or myth?
 

Not to argue, but if energy does not kill, then why would point-blankmuzzle blast kill you even if the bullet missed, why will high levels of sound kill, why will you see splits and trauma in hearts of animals that were not Heart-Shot?

RE: knockdown power... fact or myth?
 

Knockdown Power.... Fact or Myth?

As always it depends on your definition of "knockdown power" and that is the challenge in this exercise.
Change the definition, change the answer.

The folks that study this stuff have identified over half a dozen elements and measurements seeking to quantify the elements of "killing power". In most cases someone from the other side can make some sort ofargument against what is offered, hence hardly worthwhile to dive into that brain damage.

I will say this though ---going for something more fundamental....
Leaving out CNS shots, hunt the same game species multiple times under challenging field conditions (no blindhunting)firstusingweaponry with light bulletsandnarrow calibers and then do the same with the heavy bullets and wide calibers (medium velocity or better).Whenyou're done observing many well aimed shots and the corresponding differences in the game's "reaction to impact", then I am confident you will know (ata very fundamental,base level) the difference in what Ipersonally call "knockdown power."

When the sound you hear come back to you from the impact on game isakin to a5 pound sledge striking a saddle pommel following a full house swing, then you know you're getting there.... K-THUD.

IMHO, one of the more notablebenefits of ample "knock down power" becomes apparent when thingsaren't just right/or don't go just rightand you're on a mission to go out there and get'er done sometime before next week because it is a 5 day season and that bad boy isn't "whitetail posing" properly.

RE: knockdown power... fact or myth?
 

I agree that a bigger chambering with more energy has a better chance of knocking a deer down than a small cal with alot less energy and velocity. And it comes in handy when the deer is quartering towards and you need to bust the shoulder. I like to use an adequete cartridge, such as 30-06, 270, etc. I wont deer hunt with a 223 :D
I know thats its said that knockdown is a myth, but to me, id think a 300 win mag would do it before a 243, so theres gotta be something to it. I mean, theres really no evidence either way.