Knockdown power myths
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Georgiashooter
Well-Known Member
Over the years I've had deer flip over backwards after being shot with cartridges from 6mm rem to 300 WIN. It's not a myth but certainly not the .270.
I would choose my cartridge based on the game I hunt and the ranges at which I expect to shoot
I would choose my cartridge based on the game I hunt and the ranges at which I expect to shoot
.270 Win/AI, SS, WSM, WBTY, .270-300 Win, etc? Description is exaggerated but the .277 caliber/chambering is a very good LRH/S round, esp with the heavy bullets available today, ie. 170 Berger, 168 Hammer Bullets, and the now discontinued 165/175 Matrix VLD.
I shoot the 175 Matrix out of my .270 AI, not far but harvested MT muley buck at 311 yards DRT. At 1K yards, it has a calculated 1729 FPS and 1162 FPE.
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RockyMtnMT
Official LRH Sponsor
"Knock down power" is a Hollywood myth. Deer flipping over backwards and such is a physical reaction to the impact. Animals suddenly dropping like hit with lightning is a product of the central nervous system being interrupted. Sometimes a perfect lung shot will cause a "drt" result due to the impact being at the perfect moment to cause the blood pressure to spike and cause an effect like a massive stroke. We all really like it when this happens, but it should not be counted on with any chambering or bullet combo.
Bullets kill by tearing tissue in order to cause rapid blood loss which causes the central nervous system to shut down. So that physical knock down is not the effect of the bullet hitting with the force of a truck. If the bullet hit the target and bounced off like hitting a steel target thus "dumping" all of its energy, no big game animal would be knocked down. You could hit them harder with your fist.
Feenix is correct the 270cal is a fine performer. Pick the right bullet to go with the twist of the barrel and use it to distances that it is effective. That goes for all cartridges. There is no magic.
Steve
Bullets kill by tearing tissue in order to cause rapid blood loss which causes the central nervous system to shut down. So that physical knock down is not the effect of the bullet hitting with the force of a truck. If the bullet hit the target and bounced off like hitting a steel target thus "dumping" all of its energy, no big game animal would be knocked down. You could hit them harder with your fist.
Feenix is correct the 270cal is a fine performer. Pick the right bullet to go with the twist of the barrel and use it to distances that it is effective. That goes for all cartridges. There is no magic.
Steve
Pharmseller
Well-Known Member
A rather divisive discussion.
Knockdown power is a myth - www.ifish.net
And yes, knockdown power is a myth.
P
Knockdown power is a myth - www.ifish.net
And yes, knockdown power is a myth.
P
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Varmint Hunter
Well-Known Member
"Knock down power" seems to be more about shot placement than it does about cartridge selection. FWIW my 270 Win killed deer reliably but never knocked one down. 
Ask "Dirty Harry"
baldhunter
Well-Known Member
Yes bullet placement is the big factor,the other is what type of bullet and the speed of the bullet and how it performs once it makes contact.Same bullets,hitting the same tissue,one running say,2700fps,the other running 3000fps,the slower bullet will likely mushroom less than the faster bullet,creating a different wound channel and the reaction of the animal will probably be different too.A cup and core bullet the same weight as one that is bonded will also give you totally different results.So really,I believe the knockdown power has a lot to do with the bullet construction,speed and how the bullet performs once the animal is hit.
Georgiashooter
Well-Known Member
I think Baldhunter hit the nail on the head. Bullet type/construction and velocity have more to do with "knockdown" power than anything to an extent. You can change a .223 from a varmint gun to an effective deer rifle just by going from a 55 grain frangible to a 55 grain Barnes. I've done that personally.
12valvetater
Well-Known Member
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- Mar 21, 2011
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I hit a whitetail buck with my 30-338 win at about 50 yards with a 168 hunting vld in the front shoulder. It flipped him completely over and he got back up like right now. I put another one into him a little high wasting the spine and putting him down for good before he could make it into the swamp. Knockdown energy is only one part of the complex equation.
J E Custom
Well-Known Member
Rather than get into a long debate, Here is some information that should help explain Knockdown
power.
https://en.wikipedia.org/wiki/Taylor_KO_Factor
This is just a guide a for selecting the best cartridge/bullet size for the game, A well placed shot of any size will generally kill anything, it is just how long it takes the game to die that make the difference.
J E CUSTOM
power.
https://en.wikipedia.org/wiki/Taylor_KO_Factor
This is just a guide a for selecting the best cartridge/bullet size for the game, A well placed shot of any size will generally kill anything, it is just how long it takes the game to die that make the difference.
J E CUSTOM
Agreed! In 2013, I shot a MT bull elk at 931 yards with 190 Berger VLD handload out my .300 WM, shot him at front chest area (the internal organs are all souped up) but still managed to run ~200 yards. My hunting shot another bull elk from the same herd at <300 yards with factory HSM 180 Berger out of his 7MM Mag and the bull was DRT (lung shot).
Two weeks earlier, it took my other hunting buddy 3 shots (2 pass through lung area and 1 through front left shoulder) using factory 180 Barnes TTSX.
IMHO, all bullets used performed as advertised but the all the elk expired differently.
RockyMtnMT
Official LRH Sponsor
Exactly. It is the tissue damage that does the work. Bullets from a shoulder fired gun do not have the physical ability to knock down or push over a big game animal. As in knock them off their feet. If they expire very rapidly and have a muscle twitch at the same time it gives the appearance that they were lifted off their feet. It was not the bullet making the animal airborne, it is not physically possible. Many variables at play in how quickly an animal expires. Only if the cns is interrupted on impact to they drop to the shot. Otherwise they need to bleed out to shut down the cns. Unless spine is hit this usually takes a few seconds and if an animal is in the flight mode they will cover a 100y in 5 seconds. A five second death is great bullet performance. A hunter has to remember that an animal can run really far in a very short amount of time. Sometimes animals hit with big bullets show zero sign of being hit as if they did not even feel it, with soup for lungs. They walk a little ways and tip over.
Hunters should never assume they have knock down power and always assume that they hit their target.
Steve
