For many years I have wondered why an unusual calculation is always used to determine a bullets power when it contradicts the true determination of Ft/lbs of energy.
Muzzle energy = weight in grains x (velocity in feet per second squared) / 450240 or 450380 depending on your source.
Ft. lbs. = weight in lbs x velocity
In the case of bullets this is determined by weight in grains/ 7040( which is the number of grains in one lb.) x velocity.
i.e.
.223 with 55 grain bullet at 3300 ft per sec = 25.8 ft lbs of energy VS 1330 ft. lbs of energy
.308 with 150 grain at 2800 = 59.6 VS 2611
.45 acp 230 grain at 850 = 27.8 VS 369
12 guage slug with 440 grain at 1600 = 100 VS 2502
Interestingly enough Taylors KO formula also takes into consideration bullet momentum in the calculation. Its only modifier is that he included the bullet diameter. He also simpified the figure 7040 into 7000 even.
Bullet momentum is directly related to how much effect the bullet will have on a steel plate or in the actual force delivered to an animal or man.
So why do the gun magazines and ballistics table use "muzzle energy"?
Are you still a skeptic?
Than take into consideration the felt recoild between a .308 and a 12 guage slug round. The 12 guage easily has almost twice the recoil. When we compare actual bullet momentum between the two........
59.6 VS 100 we can easily see the ratio is very close to what we feel in recoil. Keep also in consideration that for every action there is an equal and opposite reaction.
If the 12 guage and .308 share similiar "muzzle energy" than why would the 12 guage kick harder?
Muzzle energy = weight in grains x (velocity in feet per second squared) / 450240 or 450380 depending on your source.
Ft. lbs. = weight in lbs x velocity
In the case of bullets this is determined by weight in grains/ 7040( which is the number of grains in one lb.) x velocity.
i.e.
.223 with 55 grain bullet at 3300 ft per sec = 25.8 ft lbs of energy VS 1330 ft. lbs of energy
.308 with 150 grain at 2800 = 59.6 VS 2611
.45 acp 230 grain at 850 = 27.8 VS 369
12 guage slug with 440 grain at 1600 = 100 VS 2502
Interestingly enough Taylors KO formula also takes into consideration bullet momentum in the calculation. Its only modifier is that he included the bullet diameter. He also simpified the figure 7040 into 7000 even.
Bullet momentum is directly related to how much effect the bullet will have on a steel plate or in the actual force delivered to an animal or man.
So why do the gun magazines and ballistics table use "muzzle energy"?
Are you still a skeptic?
Than take into consideration the felt recoild between a .308 and a 12 guage slug round. The 12 guage easily has almost twice the recoil. When we compare actual bullet momentum between the two........
59.6 VS 100 we can easily see the ratio is very close to what we feel in recoil. Keep also in consideration that for every action there is an equal and opposite reaction.
If the 12 guage and .308 share similiar "muzzle energy" than why would the 12 guage kick harder?