BDHUNTR

In my opinion, most of what people describe as "knockdown power" is a bunch of hooey. Even a .50 BMG will not knock a buck completely off its feet. That being said, you can shoot deer (or other big game) in the right spot with the right bullet and kill it where it stands. "That" type of kill is what I believe most people refer to a "knockdown power."

Any decent bullet that enters the brain or severs the spine will kill a game animal pretty much instantaneously. A bullet through both lungs tends to down them with 25-50 yards, while a heart-shot animal can run from 75-100 yards or more. Lung and heart shots kill by destruction of tissue and blood loss, and a ragged hole through both lungs bleeds more profusely than a hole in the heart. Sounds crazy, but the heart is a strong muscle, and a bullet hole will open and close as the heart beats, while the lung tissue will spurt blood like a garden hose.

That is why a bullet that passes through the aorta and surrounding arteries/veins is a great shot. If the aorta is destroyed, the entire oxygenated blood supply enters into the body cavity. Once this occurs, the brain will rapidly be depleted of oxygen and the animal will fall unconscious and die quickly.

All that being said, the quickest kills I have made on deer have been shot with my .30-06 and 165-grain Nosler Ballistic Tips. In almost every case the bullet has completely destroyed either one or both lungs, the heart or the spine. None of the deer so shot made an additional step after receiving the bullet. I will agree that if a game animal is totally unaware of the hunter, a bullet that causes less damage (say a Winchester Fail-Safe, that expands less but penetrates deeper) may drop at the shot, but if it is alerted and wary it may still run off, although dead on its feet. But when both lungs and the pipes above the heart are wrecked beyong comprehension they normally do not make it farther than ten yards.

Now, knockdown power should not be confused with stopping power, especially in the arena of dangerous game. You can kill a 550 lb lion with a .250 Savage, but I wouldn't want to try and stop a wounded Simba determined to masticate me to death with one. You need big, heavy, well-constructed bullets capable of smashing heavy bone and penetrating deeply in order to have a reliable stopping rifle. Normally you could say this starts with a 250 grain slug in a .338 Win Mag and ends at a 900 grain .600 Nitro Express.

At least that's how I see it.

Brian

bigbulls

You just answered your own question. It does not exist. There isn't a single bullet or cartridge that can be relied upon to "knock down" any animal. The only sure drop them in their tracks shot is a spine or brain shot.

Everything has to be just right to drop an animal in its tracks with a chest shot. It usually is a result of extreme shock to the circulatory system. Enough to cause massive shock to the brain from the massive shock traveling through the blood vessels from the bullet.

Now a shot through both shoulders will drop them on the spot but they will not be dead.




This past week I took a deer with my bow. Now most people would not consider a bow to have "knock down power" and I agree 100% but the deer never took another step. It droped right in its tracks. Why? Because I shot it straight down through the spine. Is this knock down power? of course not. It's severing the brain from the rest of the body.

This is just an example of how any projectile can be thought of as having "knock down power". However it simply does not exist.

NVMIKE

I know there is such a thing as knock down power. Take a 243 and a 300win mag. take an identicle double lung shot w/ each. each deer will probably die at the same time, however the 300 will knock a deer off his feet 9 out of 10 times whereas the 243 would be lucky to get 5 out of 10. Now a mortally wounded deer still on his feet can get his oh crap I've been shot system going and cover some ground, where as the deer thats been knocked off his feet RARELY gets up. thats not to say any given caliber can "KILL INSTANTLY" , but the larger ones DO make em die closer to where you shoot em.

Briman

I've seen many times more deer get knocked down and get back up and run than deer that got knocked down and stayed down.

High speed small diameter bullelts and low speed large diameter bullets all work, they just work differently.

rob1

I agree with the majority. I really think it would be hard to beat a 12 gauge slug inside of 100 yards for knock down power, even with a 45-70 or 450 Marlin, although they are pretty close if factory loaded. Factory loaded, the 450 will deliver 3426 ft. pounds of energy at 100 yards, using a 350 gr. Hornady bullet at 2100 fps., the 12 gauge shooting a 385 grain Winchester Supreme Gold sabot traveling at 2100 fps will deliver 3769 foot pounds at the same distance. In my experience, if you shoot'em through the lungs, they're gonna run a little no matter what you shoot'em with because they didn't absorb all of the bullets energy,but if you hit'em square on the shoulder bone, even a 243 will drop'em in their tracks. By the way, the way to figure foot pounds of energy ( for those who are not sure )= bullet weight X velocity squared divided by 450395.

bigbulls

You know there was someone that decided to test this "knock down power" stuff a while back. He got a thick steel plate and stood behind it and held it at arms length. Someone shot the steel plate with a big bore rifle and the steel plate hardly moved at all. Surprisingly enough he stayed standing.[] Thousands of pounds of Kenetic energy VS. about four hundred pounds of man and steel.

A bullet will not knock anything down no matter how big the bullet is. A bullet kills by massive shock and destruction to the system not by brute force. A shock wave travels through the body and sometimes when it is close enough to the right parts it causes enough trauma to the nervous system to cause an animal to fall.

NVMIKE

Briman - I've had the exact opposite experience. With the 300win mag I have NEVER seen ANYTHING: elk, antelope, or deer get up after it was KNOCKED down, as opposed to running off and LAYING down(only had animal run at all,a 6X6 elk my wife shot-poor shot placement) With smaller calibers I have seen them get up even when knocked down, but not often, the smaller the caliber the more often it happens. Also, I pointedly did NOT say small and fast wasn't as good as big and slow. I said that one doesn't kill any better than the other just that small/fast allows em to run more before expireing. Which is almost exactly what you said.

bigbulls

Question...... When these animals get "knocked down" to they usually just have their legs collapse and they drop straight down or do they actually get knocked sideways off their feet?

I have never seen any gun knock an animal sideways off its feet.

NVMIKE

Bigbulls - I think you should watch Heraldo Rivera's experience w/ the 44 mag and the bullet proof vest. It KNOCKED him down. Old heraldo was speechless. That there's funny , I dont care who you are.

Virginia7

Generally, I'd go with 35cal. and above for "knockdown" power - 358Win., 350Rem.Mag,
or 35Whelen. However, I have knocked 'em off their feet with smaller calibers also.
The first I recall was a mule deer doe, uphill shot, lung hit just behind the shoulder with a 308Win., 150gr. soft point @ approx. 125yds. She hit the ground so hard she literally bounced. Kicked a few times, and that was all. The bullet had angled upward, and the wound channel came within a couple inches of the spine. I've dropped two others in their tracks with 308Win., 150gr. also - one at 30yds., other at approx. 50yds.
Another was a 7mmRem.Mag. used on a BIG buck mule deer. Again, an uphill shot.
My friend shot, and the buck HIT the ground. Again, a few kicks, and that was it. Never
took a step.
Another friend used a 260Rem. on a whitetail last year (level ground - no up/down angles), and the doe dropped in her tracks.
My 358Win. is my favorite though, for whitetails. I use the Win. factory 200gr. loads. One hit behind shoulders, and dropped in it's tracks. Another was hit front facing. It ran
approx. 20yds., and dropped. A third was hit, and ran about 75yds.+/-. Of course, the bullet had cut down a 2" diameter tree enroute to the deer - never seen tree, guess it
was "covered" by the verticle crosshair in scope. Guess the tree took a little steam out of that one before it hit the deer.
Given a reasonable caliber, good bullet of decent weight, it mostly just depends on good shot placement, and if the animal is alerted/pumping any adrenalin or not.