Quote Originally Posted by rsterne View Post
I've been playing with some numbers this afternoon, and I'll throw this idea out there just for discussion.... It is similar to the long standing idea of having a minimum of 1 FPE of energy per pound of body weight of the target.... I am a firm believer in the relationship between momentum and killing power.... While things like the Meplat diameter affect the diameter of the wound channel, and the sectional density (or the sectional density but using the meplat diameter instead of the caliber) affects the penetration.... you still have to hit an animal hard enough to kill it.... and the bigger it is, the harder you have to hit it....

The momentum of a bullet at impact is the weight in lbs. times the velocity in fps.... That works out to the weight in grains divided by (7000 times 32.4) times the velocity in fps.... ie W (gr.) x V (fps) / 226,800.... The resulting number would be about 0.8 for a 200 gr. bullet travelling at 900 fps.... pretty hard to relate to the weight of an animal.... If instead of dividing by 226,800 we divide by 1000, the number is now 180.... hmmmmmmmmm.... would a 200 gr. bullet travelling at 900 fps (at impact) drop a 180 lb. animal?.... I would think that would be pretty close....

Here are some other examples....

8 gr. @ 450 fps = 3.6 lbs (low powered .177)
8 gr. @ 900 fps = 7.2 lbs (high powered .177)



Bob
Let's not get any misconceptions going here- it will save a lot of actual "in the field" grief...

First off, a pellet is a pi$$ poor projectile to hunt with- especially at the lower end velocities alluded to at the start of the list. If you aren't capable of head shots at those low velocities, don't shoot. Those low velocity numbers in .177 are extremely marginal on live game- anything other than a head shot will result in a wounded animal on the run or fly.

I think we need to see more on terminal ballistics- how various projectiles behave on impact. Most pellets I've seen at low to mid range velocities are over-penetrators- they simply pass through the game without expanding... a precise hit in the vitals, or head becomes the absolute minimum requirement.

Your numbers make more sense to me in the .30 cal/9mm range and up- they equal what is seen from most powder burning handguns.

Regards,

Doc Sharptail