Velocity and penetration

[cheyenne]

I've been thinking about this for a while in regards to hunting and/or bear defense. I think Linebaugh may have covered it at some point, but I can't find the writing.

Basically, at what point is adding velocity to our "non-expanding" handgun bullets a wasted effort in terms of penetration? I understand that even the hard-cast bullets will expand, and that the faster they are going, the more they will expand, and that is what causes the diminishing returns. But, if my concern is busting through both sides of an elk or penetrating to the vitals of a bear or penetrating a bear skull or breaking down his shoulder, will I reach a point of diminishing returns with velocity? If I can shoot a .44 250gr at 950fps better (i.e. quicker follow-up shots, more accurately) than the same bullet at 1300 fps, I ought to be considering what the velocity is buying me in terminal ballistics. I know the velocity is getting me a flatter trajectory, but we can ignore that for now.

Any experiences, articles, whatever is greatly appreciated. I'm not trying to start a bear defense debate, that's just one of the applications I think demands maximum penetration and a balance with shootability.

Thanks.

[whitworth]

In a nutshell: If the bullet is up to the task, more velocity buys you more penetration. Higher velocity will also create more damage.

[Encore64]

But sometimes smaller bores penetrate better than big bores.

This is not exactly a news flash. The same was discovered many moons ago with the Nitro Express Cartridges.

A wider wound channel and a deeper wound channel aren't always synonymous.

Also, when bullets are too hard they will shatter.

It's a subject of lifetime learning. But, no forum has more knowledge than this one.

[whitworth]

Sept 29, 2020 17:45:53 GMT -5 Encore64 said:

But sometimes smaller bores penetrate better than big bores.

This is not exactly a news flash. The same was discovered many moons ago with the Nitro Express Cartridges.

A wider wound channel and a deeper wound channel aren't always synonymous.

Also, when bullets are too hard they will shatter.

It's a subject of lifetime learning. But, no forum has more knowledge than this one.

They shatter is they are cast and brittle. Won’t happen to copper or brass.

[Encore64]

Sept 29, 2020 18:36:19 GMT -5 whitworth said:

Sept 29, 2020 17:45:53 GMT -5 Encore64 said:

But sometimes smaller bores penetrate better than big bores.

This is not exactly a news flash. The same was discovered many moons ago with the Nitro Express Cartridges.

A wider wound channel and a deeper wound channel aren't always synonymous.

Also, when bullets are too hard they will shatter.

It's a subject of lifetime learning. But, no forum has more knowledge than this one.

They shatter is they are cast and brittle. Won’t happen to copper or brass.

True...

[Fowler]

In a nutshell as I understand it and Newton’s laws of physics, here is my basic understanding. The faster something travels the faster it stops because the molecules the mass it is pushing through must get out of the way for the bullet to travel through..

A good cast bullet will have a large flat meplat for the face of the bullet disturbing a lot of matter as it cuts through the animal but that creates a lot of resistance as well. Now a full metal spitzer bullet penetrates an enormous amount because the pointy bullet pushes very little matter out mid the way as it travels. But it also for the same reason does very little damage so we use expanding bullets to cut and damage the vitals of the animal as it cuts through.

Handgun and heavy levergun bullets have a lot of weight behind the nose to create momentum and create a deep wound path where expanding rifle bullets typically have half the mass of these cast bullets (For their length in relation the the expanded nose) and are asked to expand to the same diameter as the cast bullets start at.

Linebaugh proved over and over that at roughly 1250fps you have achieved all the penetration a cast bullet will give you for its mass. If you want more penetration than say a 250gr 44mag bullet at 1250fps then you are better served going to a 300gr bullet than a higher velocity if we are simply looking for penetration. Driving the same 250gr bullet 20% higher in velocity might buy you 2% more penetration is all.

But more velocity will flatten your trajectory (pretty meaningless at handgun speeds) but it will also create a wider wound channel through the animal as it penetrates. The wound channel is what kills and so this is a important detail. Also penetration only goes so far, once it has gone through the animal the rest is immaterial. I mean really who care how far the Bullet bounces down the mountain after exit?

Beartooth bullets used to have a really excellent article that discussed this in great detail but that section of his website has been list for the last few years.

What is the magic formula? There isn’t one really. I personally shoot moderate velocities much better than edge of cartridge capability better and I will always take accuracy over power as long as the power is enough for the task at hand. I have my velocity window I generally am comfortable shooting in and tend to go to a bigger bullet over more velocity but that is the trade offs I have chosen.

YMMV

[whitworth]

The velocity ceiling will keep the material distortion to a minimum. In my humble opinion, the material is the only reason 1,250 fps is considered by some to be a sweet spot.

[sixshot]

I didn't see where anyone said how big our bear was & that can make quite a difference. Having said that we all know some very large Alaskan bears have been killed with the mighty 9mm in experienced hands. When shooting bears I think the most important factor is probably bullet weight over bullet velocity although both certainly come into play.
Big, heavy bullets, at least 250 grs or better are good bear medicine with quality placement but we also know that when you step into the ring with a first rate opponent you had better have first rate bullets which in this case might be the best jacketed bullet you can buy, just for insurance. Bears kill for a living, why risk your life or someone else's if there's something better you can shoot.
A person that makes brittle cast bullets doesn't know what he's doing, a person that is under gunned doesn't know what he's doing. If you're in bear country use the very best gun & bullet you can shoot well. Isn't that just common sense?

Dick

[whitworth]

Sept 29, 2020 20:43:52 GMT -5 sixshot said:

I didn't see where anyone said how big our bear was & that can make quite a difference. Having said that we all know some very large Alaskan bears have been killed with the mighty 9mm in experienced hands. When shooting bears I think the most important factor is probably bullet weight over bullet velocity although both certainly come into play.
Big, heavy bullets, at least 250 grs or better are good bear medicine with quality placement but we also know that when you step into the ring with a first rate opponent you had better have first rate bullets which in this case might be the best jacketed bullet you can buy, just for insurance. Bears kill for a living, why risk your life or someone else's if there's something better you can shoot.
A person that makes brittle cast bullets doesn't know what he's doing, a person that is under gunned doesn't know what he's doing. If you're in bear country use the very best gun & bullet you can shoot well. Isn't that just common sense?

Dick

Amen. This is not an arena where one should cut corners or save pennies.

My point was that the velocity ceiling is set to maintain the bullet’s integrity so that it will perform as designed.

[sixshot]

My point, with the all metal bullets is that I don't believe there is a velocity ceiling, at least within reason. The real factor is, can the shooter manage the recoil. Some can & some can't & many times the very top end velocities aren't needed but it's there just in case.
As far as cast bullets are concerned you can easily go beyond 1250 fps with quality cast without getting into brittle bullets & have very fine success if you know how to make the correct alloy. It's not rocket science to do this, but it does take the correct metals.
Remember a few months back when Dr. Larry Rogers used a quality cast bullet to take a high record book Rino in Africa with great success. It's pretty obvious the bullets worked just fine & he had one of the top 3-4 Rino's ever taken with a revolver. There's no need to ever feel under gunned when shooting cast if you use the correct alloy and shoot it the correct velocity. If you try to over drive it, yes it can fail. But, over driving it takes some doing & bad bullet placement has something to do with that. Good bullets & good placement can overcome just about anything.

Dick

[foxtrapper]

Excellent thread!!

[whitworth]

Or go with monolithic bullets and further stack the deck in your favor, thereby eliminating concern and eliminate the need to limit shot angles.

[boolitdesigner]

When I first started reading about big bears, Phil Shoemaker was killing them with a compact 458 Win Mag while guiding. The last one he killed while fishing was with a 9mm. His daughter used the 357 Mag I believe. You figure he knows something the rest of us don't or can't keep straight........ that is probably placement with enough penetration. I tend toward sixshot's posts more than others, but there are some points we are apart on. As a boy I watched my grandfather and great uncle kill 1200 pound steers with the 22 short.... a minuscule cartridge with just enough penetration to do the job. One shot at a precise place caused the steer to fold its legs and drop on them upright and stone dead. Put the shot in the right place and it happens.

[whitworth]

Sept 30, 2020 13:49:55 GMT -5 boolitdesigner said:

As a boy I watched my grandfather and great uncle kill 1200 pound steers with the 22 short.... a minuscule cartridge with just enough penetration to do the job. One shot at a precise place caused the steer to fold its legs and drop on them upright and stone dead. Put the shot in the right place and it happens.

Brain any animal and that’s the case. But in that example you’re essentially talking about an execution style killing, something that’s far removed from hunting and/or animal defense.

[boolitdesigner]

Bell's thousand plus Elephants qualify as executions then..... or the man knew how, where and when to shoot with very light calibers for the game......... plus having excellent mental control as well as brass ones. No, I don't agree with you. I doubt Phil Shoemaker and some other folks would either. It's all about placing a bullet accurately at a precise moment in time....... However that occurs.