The ENERGY MYTH...and it's constant resurgence.

[303Guy]

I switched over from Imperial to metric during high school and to SI at college a few years later. It's a way easier system to work with. There are no 'constants' in formulae and so on. The bug bear with SI is mass and force. A kilogram weighs 9.807 Newtons at sea level (standard gravity). The link between force (Newtons) and mass is acceleration. 1 Newton acting on 1kg produces acceleration if 1 m/s². Gravity produces 9.807 m/s². People do still talk of kg force which is an anomaly. Momentum is mass x velocity = kgm/s² = Ns (Newton seconds) = force x time. So, momentum is force x time. An impulse is also force x time. A smaller force applied over a longer time produces the same impulse as a larger force applied over a shorter time. Think heavier, slower bullet versus lighter, faster boolit.

My particular heavy , slow boolit, the 240gr 44, that failed to fully penetrate a cat sized critter, failed because the force was being applied slow enough for the critter to move with the boolit thus absorbing the impulse, something like riding a punch. By the way, had that critter been alive it would have died instantly I'm sure. I was expecting it to explode!

Anyway, nothing changes, just that momentum is an important factor in boolit performance. Energy is probably more important but not over-riding. I've said before, when it comes to hunting I do not consider energy at all - I have no idea of energy (or momentum) figures. Neither matter. Only velocity, boolit mass and frontal area (effective sectional density). That and what I know about bullet performance which is empirical anyway (some of that is from what I've learned from you guys reported experiences).

By the way, what does a white tail deer weigh?

[grumman581]

By the way, what does a white tail deer weigh?

There are quite a few subspecies and the size varies.

http://en.wikipedia.org/wiki/White-t...ize_and_weight

[303Guy]

Thanks, grumman581. So does the statement that the 30-30 is 'ideal' for white tail encompass the larger specimens but the rare monster specimens would be at closer ranges?

Having determined the weight range of goats, I compared that to the OGW from JBM for a 55gr 223 bullet with 2700 fps muzzle velocity and the correlation to my field results is pretty good. The range limitation I self imposed for different size goats also correlates well.

The same applies for the 30-30 and white tail deer using 150gr RN (couldn't find a FN example bullet). Up 500 lb real close down to 160 lb at 200 yds. I see White tail can vary from 130 lbs to 290 lbs (with one monster specimen of 510 lbs being recorded).

Red deer range from 260 lbs to 370 lbs. In my estimation the 30-30 is a little under powered for red deer. No experience there, just what I would estimate - unless real close (all our red deer tend to be on the larger side from what I've seen). I consider the 303 Brit marginal for them yet I've seen one DRT with a 7-08 and I know they get taken with 6.5's with 140gr bullets. So maybe I tend to under estimate game size for caliber.

[singleshot]

The human body is 50-65% water. Here's a table of the speed of sound in water:

http://www.engineeringtoolbox.com/so...ter-d_598.html

None of *my* rifles shoot a projectile that fast.

And it just so happens that the "average" speed of sound in any critter is about 60% or so of the speed of sound in water...when you strike a critter above the critical velocity, you have a different set of principles at play when it comes to terminal ballistics. A super-sonic shock wave in flesh produces entirely different results than a sub-sonic shock wave in the same flesh. I don't feel like typing a treatise on the subject, but here's another "bone" to keep the discussion going.

[singleshot]

And it just so happens that this velocity usually falls somewhere around 2400 fps for mammals...as a rough figure. If the projectile drops below the speed of sound in that critter, the damage to flesh should also change accordingly. Of course, instrumenting live critters for testing could prove quite tricky.

[jonp]

When most people speak of whitetail they are talking about O. virginianus. I have personally seen them taken in our camp in Northern New England over 300lbs although that is rare. 250lb deer are taken every year. Although they can be large they have a thin skin and are not necessarily hard to kill given a proper shot placement. I took a nice field dressed 180lb with an open sight GP100 and a 165gr bullet at 35 yards. Within a reasonable distance which has been lengthened somewhat with the lever revolution bullets a 30-30 will work quite nicely.
People may and will argue with me but I think that 30-30 was designed for the Whitetail to be taken with iron sights so I would limit my shots with it to what I could do with those. For me that was never much beyond 150yrds when I was younger. Considering the majority of deer are taken in mixed cover and hardwoods that seems to be a good rule of thumb. Of course if you are sitting a stand on the edge of a cornfield in the mid-west or a bean field in the southeast the 30-30 would not be adequate at all.

[Capt. Methane]

Slugs.

Doh! Still, for comedic effect it sounded better with stones than slugs- I put salt on slugs...stones get tossed out of the garden!

To give people units that they were familiar with, we came up with lbf and lbm (pounds-force and pounds-mass). 1 pound-force = 1 pound-mass at 1 standard gravity.

They do the same thing with the kilogram-treat it as if one kg mass weighs one kg at standard gravity.

Of course by that convention it would "weigh" 1/6th of a kg on the moon even though it's mass has not changed. I get it, was just trying to inject a little much needed levity.

[grumman581]

Doh! Still, for comedic effect it sounded better with stones than slugs- I put salt on slugs...stones get tossed out of the garden!

They do the same thing with the kilogram-treat it as if one kg mass weighs one kg at standard gravity.

Of course by that convention it would "weigh" 1/6th of a kg on the moon even though it's mass has not changed. I get it, was just trying to inject a little much needed levity.

OK... I thought you were implying that the "stone" (Imperial measurement system) was a measure of mass.

[grumman581]

Thanks, grumman581. So does the statement that the 30-30 is 'ideal' for white tail encompass the larger specimens but the rare monster specimens would be at closer ranges?

Having determined the weight range of goats, I compared that to the OGW from JBM for a 55gr 223 bullet with 2700 fps muzzle velocity and the correlation to my field results is pretty good. The range limitation I self imposed for different size goats also correlates well.

The same applies for the 30-30 and white tail deer using 150gr RN (couldn't find a FN example bullet). Up 500 lb real close down to 160 lb at 200 yds. I see White tail can vary from 130 lbs to 290 lbs (with one monster specimen of 510 lbs being recorded).

Red deer range from 260 lbs to 370 lbs. In my estimation the 30-30 is a little under powered for red deer. No experience there, just what I would estimate - unless real close (all our red deer tend to be on the larger side from what I've seen). I consider the 303 Brit marginal for them yet I've seen one DRT with a 7-08 and I know they get taken with 6.5's with 140gr bullets. So maybe I tend to under estimate game size for caliber.

When I was a kid, my first deer rifle was a .30-30. Usually hunting in thick brush with iron sights, so if the deer was further than 50 yards away, you wouldn't see it. In some of the areas, you wouldn't see anything past 10 yards.

These days, I don't have the .30-30 anymore, but I have quite a few other rifle calibers -- .300 win mag, 7.62x51, 7.62x39, 5.56x45, and .45-70. I choose the .45-70, but I hunt hogs and I don't want to have to say that I didn't "bring enough gun". The deer locally are rather small and not worth the trouble of harvesting anyway. Besides, they're too damn tame and no challenge. I was pulling into my subdivison the other night and saw some deer across from the entrance to the subdivision in the front yard of the elementary school. I circled around to take a look and there were 10 of them -- mostly does though. They glanced up once or twice and then continued eating.