Impact energy VS Penetration

This is an interesting subject that leads to long discussions. :) The sectional density parameter as it relates to potential penetration is valid only for as long as the bullet remains undeformed along its path at the ballistic terminal end of travel. Sectional Density = Mass /Diameter (squared). The other variables that are difficult to pin down, analyze and predict are spin stabilization and mass forward of aerodynamic pressure stabilization within the dense media at the terminal end. Very generally I think momentum is the parameter that best describes the penetration potential for a bullet compared to other bullets with similar SDs. But again it's not a perfectly simple comparison because so many other variables may be at play between any two bullets.

One of the buggers in trying to predict or even fully understand bullet behavior, scientifically/mathematically, is the real but mostly overlooked conflict between the concepts of kinetic energy and momentum. As it turns out energy, as defined, is usually the enemy of penetration while momentum is the friend. By definition, energy is two parted- the harder a bullet pushes on any substance, air or more dense material- doesn't matter, the harder the substance pushes back (and the results of that push back is seen in the deformation of the bullet). And that kinetic energy concept is why even a little 22 rf will leave a relatively huge crater in wet clay. While at first glance energy and momentum seem to be very closely related (or even the same) they are in reality two very different things that have to be looked at differently in the context of ballistics.

What all this means in practical terms- I dunno? other than it is interesting to think about. And sometimes you can look at bullet behavior and, at least in some small way, understand why the bullet did what it did. Or, given some parameters of design, possibly predict a behavior. :)

Then what's most interesting to me is actually testing a bullet in media and comparing that to what the prediction is. There are always surprises along the way. One example: I was testing a large caliber, near pure lead cast bullet at very modest impact velocity in wetpack media. The penetration was far greater than I had predicted and equalled the very best of high velocity, jacketed controlled expanding bullets.
 
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375 Ruger Fan, yes in one respect you are correct. The 404 Jeffery shoots a bullet that is
0.423" and weighs 400 Gr. pushed by 84 Grs. of H4350 for a velocity of 2300 FPS. The 416 Rigby shoots a bullet that is 0.416" diameter and weighs 400 Gr. pushed by 92 Grs of the same H4350 for a velocity of 2400 FPS or possibly a little better. In short the Rigby edges the Jeffery a little bit.
 
This is certainly a very complex question @norfolk shooter. Use a good quality bullet from your 416 and you will get all the penetration you require. If you require more penetration make sure its "solid";)
 
Sometimes people are unable to read and understand what was written without filtering it through THEIR own prejudices.

Apologies, but Inigo Montoya was calling from beyond the grave. "You keep using that word. I do not think it means what you think it means."

I'm going to go back to fondling my .458 Lott and not worrying about momentum or energy. I'm sure I have enough.
 
Apologies, but Inigo Montoya was calling from beyond the grave. "You keep using that word. I do not think it means what you think it means."

I'm going to go back to fondling my .458 Lott and not worrying about momentum or energy. I'm sure I have enough.

The 500gr bullet caliber .458 is also almost ideal in terms of penetration. Unfortunately it needs an velocity that not every cartridge caliber .458 delivers.
 
Apologies, but Inigo Montoya was calling from beyond the grave. "You keep using that word. I do not think it means what you think it means."

I'm going to go back to fondling my .458 Lott and not worrying about momentum or energy. I'm sure I have enough.

Based on what I've experienced in the field and of my own testing, if using quality bullets designed for the task, for everything including thick skinned DG, you most certainly have enough penetration with the Lott!! :)
 
After work I sat and cuddled my double and have come to the conclusion she is my double and I lover her none the less. A 500NE will come to me later in life I'm sure but for the next 10 or so years I'll be happy with my 416 Rigby. Thats right @IvW a 416 Rigby double rifle.

NSxx
 
After work I sat and cuddled my double and have come to the conclusion she is my double and I lover her none the less. A 500NE will come to me later in life I'm sure but for the next 10 or so years I'll be happy with my 416 Rigby. Thats right @IvW a 416 Rigby double rifle.

NSxx

Cool it is one more than I own, having only a poor man/s double suitable for leopard...of course for you the Rigby 416 double is the best as it is the one you own......

(for those that say you should have a rimed case go screw yourself))

I ques I fall in this category then...

In the meantime I will use my 500 Jeff for elephant and buff.

Does it have ejectors or extractors?
What make is it?
 
The 500gr bullet caliber .458 is also almost ideal in terms of penetration. Unfortunately it needs an velocity that not every cartridge caliber .458 delivers.
I agree with you about this. It's an interesting threshold, but I'm fortunate to over it. I love the way they feel in the hand: solid and authoritative.
Based on what I've experienced in the field and of my own testing, if using quality bullets designed for the task, for everything including thick skinned DG, you most certainly have enough penetration with the Lott!! :)
Yeah I'm very happy with the Lott. It certainly seems quite versatile especially if one toys around with .45-70 bullets, but I'm a 300gr/.375, 500gr/.458 type of guy. There's goodness and simplicity in one bullet weight per caliber when the stable gets deep.
After work I sat and cuddled my double and have come to the conclusion she is my double and I lover her none the less. A 500NE will come to me later in life I'm sure but for the next 10 or so years I'll be happy with my 416 Rigby. Thats right @IvW a 416 Rigby double rifle.

NSxx
I like to watch my favorite shows with mine and the wife is kind enough to let me stand it up next to the bed. I have been known on occasion to have it along on my night walks around the property, but the .375 is better suited with the firedot scope.
 
Cool it is one more than I own, having only a poor man/s double suitable for leopard...of course for you the Rigby 416 double is the best as it is the one you own......

(for those that say you should have a rimed case go screw yourself))

I ques I fall in this category then...

In the meantime I will use my 500 Jeff for elephant and buff.

Does it have ejectors or extractors?
What make is it?
Extractors its a sabbati and an accurate one
 
With questions such as this it's best to sort the information into two categories: What does the bullet do? and What does the animal do? Properly sorted, most questions about performance answer themselves.
 
Extractors its a sabbati and an accurate one
Extractors on a rimless case...how does that work? Sort of like an Encore where there is a bit of spring tension in to the groove and you sort of clip in and out of the extractors? How fast and smooth is that to reload for say six shots? For the record I have shot two deer in rapid succession with an Encore .300 WM pulling shells from my jacket pocket so definitely not trolling you just curious.
 
Extractors on a rimless case...how does that work? Sort of like an Encore where there is a bit of spring tension in to the groove and you sort of clip in and out of the extractors? How fast and smooth is that to reload for say six shots? For the record I have shot two deer in rapid succession with an Encore .300 WM pulling shells from my jacket pocket so definitely not trolling you just curious.
I have never seen an encore but they call the little bits pawls. Being an engineer I have looked at them and put a few shots through the rifle and the are good as gold. Many makers including merkel and H&H make double in this cal.
As for speed I can keep up with a bolt action for 4 shots thats the most we have raced. But saying that in a close charge after the first two it should be over
 
I have never seen an encore but they call the little bits pawls. Being an engineer I have looked at them and put a few shots through the rifle and the are good as gold. Many makers including merkel and H&H make double in this cal.
As for speed I can keep up with a bolt action for 4 shots thats the most we have raced. But saying that in a close charge after the first two it should be over

The Empire was built on cups of tea. When in doubt, fear, joy or any other human emotion tea is to be drunk.

You may want to change the brand.....
 

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