velocity

[DucksOnThePond]

I saw in a earlier post where someone rated 308 same as 30-06 because the velocity was the same. I know ballistics tables show velocity in ft/sec and energy in ft lbs. I was always led to believe that you needed around 1100 ft lbs of energy to have killing power for deer sized game yet alot of people seem to rate velocity as the mark of a caliber. I was just curious as to opinions as to which is the most important number - velocity or energy.

 

[HSMITH]

It takes both. I place more weight on energy, but I look for a balance that will give a reasonable trajectory (velocity) with as much energy as possible within reason. Too much velocity makes life really hard on bullets, especially if they hit a big bone, energy at a lower velocity (heavier bullet) can make all the difference. Bullet selection plays a big role here too.

It really is a complicated balancing act. A more specific question would be easier to answer without rambling, the potential interpretation of what you are asking and answers are vast.

308 and '06 are fairly close with 150's, step out to 180 and 200 grain bullets and '06 takes a considerable lead.

 

[Yankee Doodle]

1100 ft. lbs. as a minimum for deer is a bunch of Horse Hockey. The name of the game is shot placement, coupled with a good bullet. I have taken whitetails with everything fron a .38 Spl., 158 gr LSWC load, to a 250 grain .338 Win Mag. Over a close to 50 year hunting career, I have never had any deer, shot through the lungs, get away. I just can't buy the "minimum energy" reasoning. A shot in the a$$ is still a shot in the a$$, even if it's with a .460 WM. Accuracy, not energy, takes deer.
Y.D.

 

[Lancel]

The bullet's energy is derived from velocity.*

I'd rather know a bullet's velocity. From that info I can determine if the bullet is operating within it's design parameters.

Too fast means the bullet might come apart on contact on even in the air, too slow means it won't expand or penetrate properly.

Since I prefer hunting with bullets that exit the animal, energy by itself is meaningless. Who knows how fast the bullet leaves the animal or how much energy exits with it.


*(For example: Energy = bullet weight x velocity squared / 450400)


Larry

 

[Rangefinder]

As stated above, it's a balancing act that's all a part of the same equasion. Higher mass with lower velocity, or higher velocity with less mass.

Example: 600 yard shot (I'm using this distance for longest expected shot performance in a possible hunting situation)--Book text combined with field test, and in general average context.
---A .243 caliber 95 gr. bullet from a 6mm drops 66.3 inches below 100yd zero with a velocity of 1902 fps, and delivers 763 ft-lbs of energy at the point of impact.

---A .30 caliber 220 gr. bullet fired from a 30-06 drops 135.5 inches below 100yd zero with a velocity of 1236 fps. and delivers 815 ft-lbs of energy to the point of impact.

The bullet velocity vs. the bullet mass is quite different, but the energy delivered isn't too far apart. Where the difference lies in performance is the individual bullet design and what it does AFTER the impact. Size, mass, velocity, individual design in a bullet, the game hunted---it all plays a part in the same over-all equasion.