This statement was posted on another forum, and I am curious as to how many people believe that bullets traveling at a higher velocity transfer less energy because they spend less time in the expansion media. Do you believe that if the velocity was reduced, the bullet would transfer more energy, because it would spend more time in the expansion media?
Energy Transfer
- Thread starter stubblejumper
- Start date
Throttle_monkey1
CGN Ultra frequent flyer
I don't buy into the energy dump theory as what kills animals is blood loss (through organ destruction, arterial destruction, etc) or a CNS hit.
Also a bullet's expansion is not related to how much time it spends in the animal, it is dependant on the resistance of the medium it is fired into, the construction of the bullet, and the velocity.
If you fire a nosler partition into a slab of meat at 500 feet per second, it would likely penetrate but it won't expand much even though the meat offers more resistance than air because a) the partition is a tough bullet and b) it isn't moving very quickly although it would penetrate the meat slower than if it were travelling at 2500 feet per second
Also a bullet's expansion is not related to how much time it spends in the animal, it is dependant on the resistance of the medium it is fired into, the construction of the bullet, and the velocity.
If you fire a nosler partition into a slab of meat at 500 feet per second, it would likely penetrate but it won't expand much even though the meat offers more resistance than air because a) the partition is a tough bullet and b) it isn't moving very quickly although it would penetrate the meat slower than if it were travelling at 2500 feet per second
I am not interested as to whether energy transfer kills the animal or not, just in whether more velocity increases or decreases energy transfer. But please comment on expansion vs velocity, as I also hear people stating that a bullet is moving too fast to expand, and that reducing the velocity would increase expansion.
pete dobinson
CGN frequent flyer
- Location
- Courtenay BC.
Sounds like a load of codswallop to me. The faster the bullet the more energy it will have. Maybe someone's mixed up with fragile bullets that blow up on impact.
Energy transfer is a product of velocity and bullet expansion, not a product of time..... The faster a bullet moves, the more energy it has to transfer, so while it may "stay in the animal for less time" it will transfer more energy per millisecond than a slower moving counterpart....
Really, if comparing the two on an exactly identical pass through shot, with proper billet for velocity, it's a chicken egg argument....
Really, if comparing the two on an exactly identical pass through shot, with proper billet for velocity, it's a chicken egg argument....
I would think that a bullet creates more hydrostatic shock during its expansion phase than during it's expanded phase......
- Location
- Somewhere on the Hudson Bay Coast
Bullet design, material, and construction are key to their performance against the density of a living target. A bullet can be designed to perform within any impact velocity envelope you choose, against any target density from a prairie dog to an elephant.
pete dobinson
CGN frequent flyer
- Location
- Courtenay BC.
Also, a bullet should stop under the hide on the far side so that all of the energy is taken up inside the animal. Barnes bullets have been known to pencil straight through, so that there would be energy lost inside the animal.
This is going to be an interesting thread
. Lots of highly debated ballistic theories.
Tuff to imagine the physical effects on bullet speed, diameter and what not.
I tend to think of it as my butt on a motorcycle seat barreling down a highway and imagine
the impact a bug vs rain vs a stone hitting my face.
Faster you go the more hert is inflicted on me skin.
Now have a semi tire peel off at the right moment...........morto.
Shooting big ugly kritters I'd opt for something that has Magnum stamped on the barrel.
I tend to think of it as my butt on a motorcycle seat barreling down a highway and imagine
the impact a bug vs rain vs a stone hitting my face.
Faster you go the more hert is inflicted on me skin.
Now have a semi tire peel off at the right moment...........morto.
Shooting big ugly kritters I'd opt for something that has Magnum stamped on the barrel.
Nonsense. Higher velocity increases expansion. In my experience, light fast bullets kill quicker than big, heavy, slow ones.
I have a very open mind on this matter.
I sat on a goat mountain with a young son, while he killed a good billy goat with one shot from his 243. He was using factory IVI Imperial ammunition with 100 grain bullets. The bullet hit the goat broadside, was mushroomed like pictures in ads for good bullets, and stopped by the hide on the far side.
Later, I chronographed five cartridges from the box of IVI Imperial that he had shot the goat with. Five shots averaged a mere 2540 fps!!!
As a check, without even moving from my seat and using the same rifle, I ran five of my hanloads over the Oehler chronograph. The 100 grain Sierra bullet in them was loaded with 47 grains of Norma 205. The five bullets averaged a velocity of 3112 fps. I am reading these figures from the notes I made at the time.
The 30-30 Winchester cartridge, with 170 grain bullets developed for a velocity of 2200 fps, has been killing game up to moose size with great regularity for over a hundred years. Ballistic figures indicate they just shouldn't be doing this! But they do.
Even Jack O'Connor once wrote that the 30-30 with 170 grain bullets was a much better killer than figures would indicate they should be.
I sat on a goat mountain with a young son, while he killed a good billy goat with one shot from his 243. He was using factory IVI Imperial ammunition with 100 grain bullets. The bullet hit the goat broadside, was mushroomed like pictures in ads for good bullets, and stopped by the hide on the far side.
Later, I chronographed five cartridges from the box of IVI Imperial that he had shot the goat with. Five shots averaged a mere 2540 fps!!!
As a check, without even moving from my seat and using the same rifle, I ran five of my hanloads over the Oehler chronograph. The 100 grain Sierra bullet in them was loaded with 47 grains of Norma 205. The five bullets averaged a velocity of 3112 fps. I am reading these figures from the notes I made at the time.
The 30-30 Winchester cartridge, with 170 grain bullets developed for a velocity of 2200 fps, has been killing game up to moose size with great regularity for over a hundred years. Ballistic figures indicate they just shouldn't be doing this! But they do.
Even Jack O'Connor once wrote that the 30-30 with 170 grain bullets was a much better killer than figures would indicate they should be.
Purple shoulder
Regular
- Location
- Winnipeg MB
The energy a bullet has is a product of velocity and mass (mass x force). The faster its going, the more energy it has. It does not need to expand to deliver all its energy. It just needs to come to a stop in the target. If it passes through it doesn't deliver all its energy. I am NOT commenting on killing power, just physics.
Two bullets same caliber and weight travelling at the same velocity and placed in exactly the same place will produce exactly the same results, not two different ones...
I do agree that a bullet that stops in the animal has transferred all of its energy, but at the same time, that does not mean that a faster travelling bullet that passes through did not transfer more energy than the one that stopped......
Purple shoulder
Regular
- Location
- Winnipeg MB
Transfer of energy is an old an tired yard stick which tells you basically nothing about killing efficiency. Anyone want calculate the energy of a broadhead at 350 ft/s? Most bow hunters I know are elated with a pass through and less so with an arrow still in the animal. Is one surface wound better than two with a bullet out of a rifle? Of course not two wounds bleeding are much better than one. As long as the bullet expands enough to make a wide irregular wound channel there will be a lot of trauma and bleeding and the animal is done quickly and humanly, even if half the bullets energy is lost out the off side.
Throttle_monkey1
CGN Ultra frequent flyer
Back to the original topic, as others have alluded to kinetic energy is 0.5 x mass x velocity^2. A change in velocity has a much greater affect on the kinetic energy of the projectile than a change in mass.
So if you have a 150 grain projectile travelling at 2000 feet per second and it is fired into a medium and comes to rest it has transferred all of its kinetic energy to the medium (1330 ft.lbs)
Now if you fire that same projectile into the same medium at 3300 fps and it exits you need to know the exit velocity to determine the change in velocity to determine energy imparted. If it exits at 1000 feet per second it has transferred more energy than the slower projectile. If it exits with 2000 feet per second it has transferred less.
This is energy transfer only. Not killing power, bullet construction, hydrostatic shock, or whether energy dump causes death at all.
So if you have a 150 grain projectile travelling at 2000 feet per second and it is fired into a medium and comes to rest it has transferred all of its kinetic energy to the medium (1330 ft.lbs)
Now if you fire that same projectile into the same medium at 3300 fps and it exits you need to know the exit velocity to determine the change in velocity to determine energy imparted. If it exits at 1000 feet per second it has transferred more energy than the slower projectile. If it exits with 2000 feet per second it has transferred less.
This is energy transfer only. Not killing power, bullet construction, hydrostatic shock, or whether energy dump causes death at all.
A broadhead and a bullet are two completely different killing mechanisms... One is designed to kill via brute force and create hydrostatic shock and a large wound channel and the other is designed to slice through while severing blood vessels and slicing through vital organs causing a bleed out....
