Ballistics Questions on FT Per Second
#1
Thread Starter
Join Date: Jun 2006
Location:
Posts: 152
Ballistics Questions on FT Per Second
My question is on FEET per Second under 200 yards. the faster the bullet is going the harder it hits or so they say ....
Does a difference in 200 Feet per second with the same bullet make a big difference ?
So a 308 150 grain going 2600 feet per second compared to 2900 feet per second. Is there a difference ? or are you just spliting hairs.
On a perfect hit no but lets talking about ahit that was not perfect
this is on DEER over 200 pounds
Does a difference in 200 Feet per second with the same bullet make a big difference ?
So a 308 150 grain going 2600 feet per second compared to 2900 feet per second. Is there a difference ? or are you just spliting hairs.
On a perfect hit no but lets talking about ahit that was not perfect
this is on DEER over 200 pounds
#3
RE: Ballistics Questions on FT Per Second
ORIGINAL: sc003ro
My question is on FEET per Second under 200 yards. the faster the bullet is going the harder it hits or so they say ....
Does a difference in 200 Feet per second with the same bullet make a big difference ? NOPE! No big difference!!
So a 308 150 grain going 2600 feet per second compared to 2900 feet per second. Is there a difference ? or are you just spliting hairs.
On a perfect hit no but lets talking about ahit that was not perfect
this is on DEER over 200 pounds
My question is on FEET per Second under 200 yards. the faster the bullet is going the harder it hits or so they say ....
Does a difference in 200 Feet per second with the same bullet make a big difference ? NOPE! No big difference!!
So a 308 150 grain going 2600 feet per second compared to 2900 feet per second. Is there a difference ? or are you just spliting hairs.
On a perfect hit no but lets talking about ahit that was not perfect
this is on DEER over 200 pounds
IMO, there is no gun that can be fired from the shoulder by man that is powerful enough to compensate for sloppy shooting. There is sure not enough difference between a .30/'06 and a .308 for this - both calibers require good bullet placement. So does a .300 Magnum or a .416 Rigby!
(BTW, a .308 factory loadfires a 150-grain bullet at over 2800 FPS MV, AND the Federal Hi-Energy or Hornady Light Magnum loads will break 2900 FPS in the .308 with 150-grain bullets. In .308, the 2600 FPS figure is for 180-grain bullets.)
Personally, I consider the .308 Win. just about perfect for all deer hunting!
#4
Nontypical Buck
Join Date: Feb 2003
Location: Gypsum KS USA
Posts: 1,289
RE: Ballistics Questions on FT Per Second
Didn't you take high school physics?
Here's the deal:
200fps on 2900fps is a difference of about 6.9%...kinetic energy in the ideal world is measured at 1/2(mass)x(velocity)^2...so a 2900fps, 150grn bullet has approximately 2801ft.lbs. of energy while a 2700fps 150grn bullet has approximately 2428ft.lbs...a difference of 13.3%.
Energy varies proportionate with the SQUARE of velocity, so changing velocity has an exponential effect on energy, i.e. if you doubled your bullet mass, you'd only double your kinetic energy, while if you double your velocity, you get four times the energy. In other words, bullet velocity is REALLY important for energy.
NOW...as far as having enough stank to do the job....EITHER BULLET HAS PLENTY OF ENERGY!!!
Here's the REAL deal: Bullets do not perfectly translate all of their energy to the animal...especially when the bullet EXITS the animal. The body resists the bullet entering and passing through, and the bullet TYPICALLY fails somewhat (think of a soft point bullet being kind of like a crumple zone on a car)...The body is going to resist both bullets with nearly equal force, since the coefficient of friction and the moment of inertia of the body will be basically constant for either case. so while the 200fps velocity change might mean an energy difference of 13% on paper, the amount of translated energy will likely be equal....
I'm not going to run the numbers or try to recall the exact formuli right now, but when the bullet strikes, it tries to maintain it's motion...or its momentum, but the body resists and slows the bullet, absorbing a lot of this momentum. Now, the only way it can translate this momentum is while it's in contact with the body, and the slower bullet will be in contact with the body longer because it takes it longer to traverse the cross-section of the body....
SO....long story short....
EITHER bullet is going to have enough energy to kill a deer.
Here's the deal:
200fps on 2900fps is a difference of about 6.9%...kinetic energy in the ideal world is measured at 1/2(mass)x(velocity)^2...so a 2900fps, 150grn bullet has approximately 2801ft.lbs. of energy while a 2700fps 150grn bullet has approximately 2428ft.lbs...a difference of 13.3%.
Energy varies proportionate with the SQUARE of velocity, so changing velocity has an exponential effect on energy, i.e. if you doubled your bullet mass, you'd only double your kinetic energy, while if you double your velocity, you get four times the energy. In other words, bullet velocity is REALLY important for energy.
NOW...as far as having enough stank to do the job....EITHER BULLET HAS PLENTY OF ENERGY!!!
Here's the REAL deal: Bullets do not perfectly translate all of their energy to the animal...especially when the bullet EXITS the animal. The body resists the bullet entering and passing through, and the bullet TYPICALLY fails somewhat (think of a soft point bullet being kind of like a crumple zone on a car)...The body is going to resist both bullets with nearly equal force, since the coefficient of friction and the moment of inertia of the body will be basically constant for either case. so while the 200fps velocity change might mean an energy difference of 13% on paper, the amount of translated energy will likely be equal....
I'm not going to run the numbers or try to recall the exact formuli right now, but when the bullet strikes, it tries to maintain it's motion...or its momentum, but the body resists and slows the bullet, absorbing a lot of this momentum. Now, the only way it can translate this momentum is while it's in contact with the body, and the slower bullet will be in contact with the body longer because it takes it longer to traverse the cross-section of the body....
SO....long story short....
EITHER bullet is going to have enough energy to kill a deer.
#6
Giant Nontypical
Join Date: Feb 2003
Location: fort mcmurray alberta canada
Posts: 5,667
RE: Ballistics Questions on FT Per Second
In each case the bullet will have enough energy to provide a clean kill.However the bullet design and construction will have muchmore of an effect on the bullets performance on game than the energy.
#7
Thread Starter
Join Date: Jun 2006
Location:
Posts: 152
RE: Ballistics Questions on FT Per Second
Ok so to answer the question. we got a little side tracked... appreciate the feedback
200 FPS more in the same round from 2700 fps to 2900 FpS really does not make a difference on a deer under 200 yards
I think this is what you all are saying
high school physics was about 18 years ago
200 FPS more in the same round from 2700 fps to 2900 FpS really does not make a difference on a deer under 200 yards
I think this is what you all are saying
high school physics was about 18 years ago
#9
Join Date: Oct 2006
Location: Bentonville, Arkansas
Posts: 35
RE: Ballistics Questions on FT Per Second
ORIGINAL: Doe Dumper
The deer would NEVER know the difference... its all good..
The deer would NEVER know the difference... its all good..
#10
RE: Ballistics Questions on FT Per Second
"Actually I have read that deers prefer to be shot with a 30-06, thus explaining it's popularity. The deers want to be shot by it."
That's just due to habit. The old '06 has been around for over 50 years longer than the .308 Win., and deer have become accustomed to being shot by it. I believe this explains their preference, since deer are creatures of habit.........Now, bears, on the other hand,.........
That's just due to habit. The old '06 has been around for over 50 years longer than the .308 Win., and deer have become accustomed to being shot by it. I believe this explains their preference, since deer are creatures of habit.........Now, bears, on the other hand,.........