How well do heavy, hard bullets at low velocity penetrate?


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goon
August 15, 2011, 12:04 AM
When we talk of larger dangerous animals like big black bears, large boars, or brown bears, the discussion always turns to large caliber revolvers like the .44 Magnum or .45 Colt (or bigger) loaded with heavy, hard bullets that are driven about as fast as they can be without turning the shooter into a projectile.

Of course, such loads aren't always the most controllable. Suppose all you had was a .44 Magnum or .45 Colt with a standard loading pushing a hard cast bullet at a normal velocity... what kind of penetration would that have on a large, mean animal? Do those of you who have experience with such animals think that a "standard" load would be effective for defense? Is anyone aware of ballistic gel or other tests that have been used to measure the penetration of these loads? What about real stories of their use in the field?

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DTesch357
August 15, 2011, 12:19 AM
Velocity isn't everything. I cite Randy Garrett, of Garrett Cartridges. Africa's deadliest 5 have been taken with his 45-70 'Hammerhead' super hard cast lead wide flat nose bullets. They aren't the fastest, but they do penetrate like none other.

One easy way to test penetration is to shoot into wet newspaper. Randy has done this, and has some anecdotal evidence on his site; the way he puts it, "the faster they are, the faster they come to a stop."

http://www.garrettcartridges.com is his site. Fun reads, there.

Mike1234567
August 15, 2011, 01:18 AM
Slow/heavy = deeper push through.

Light/fast = shallower/faster energy dump.

Choose what you need for the animal.

goon
August 15, 2011, 01:40 AM
But what about slow and normal - that's my question. Like something approximating the original 250 Grain .45 Colt load with a good, hard bullet that has a wide meplat?

BTW - thanks for the link to Garrett's site. It was educational.

NM Mountainman
August 15, 2011, 01:45 AM
Go to the Beartooth Bullet web site and read the first Tech Note by Marshall Stanton, the owner of BTB. In that Tech Note, Mr. Stanton has some charts showing the diameter of the wound channels and the penetration depth based on meplat, weight, and velocity. Mr. Stanton was one of the original developers and advocates of hard cast heat treated bullets for hunting. In general, he favors the use of heavy, large diameter bullets, with a wide flat meplat. But, he also states that the need to use the heaviest for caliber bullets for the .44 mag has been oversold for hunting in the lower 48 states. His research along with the experience of customers in the field have demonstrated this.

For instance, according to Stanton's charts, a 250 gr. Keith style bullet has the same penetration at an impact velocity of 1100 fps as a 325 gr WLFN bullet at the same velocity. But the load with the lighter bullet will generate only 65% as much recoil as the heavier load and may give you a better opportunity to make a quick second shot. What's the catch? What do you give up besides a lot of recoil with the lighter bullet? According to Stanton, the predicted wound channel of the lighter bullet with the smaller meplat diameter will be about .1" smaller in diameter than the wound channel produced by the heavier bullet with the wider meplat. If you compare the 265 through 300 gr weights, you will discover that bullets in this weight range have a very good balance between wound channel diameter and penetration depth. All of these bullets will penetrate completely through a black bear or grizzly with an impact velocity of 1100 fps according to Stanton.

Flat nosed hard cast revolver bullets impacting at moderate velocity have penetration to spare. You give up no penetration by using a lighter bullet with a slightly smaller meplat. Buffalo Bore sells a "reduced recoil" .44 mag load for use in lightweight .44 mag revolvers with short barrels. The load propels a 250 gr Keith style hard cast bullet at 1250 fps from a 4" barrel. According to Stanton, it will get 'er done.

All of the above is based on Stanton's research. My elk and mule deer hunting was done with a .44 mag using JSP bullets (not hollow points) in the 240 to 270 weight range. These loads gave modest expansion (sometimes very little) and great penetration at impact velocities around 1100 to 1200 fps. Using strongly constructed controlled expansion bonded JSP's, there is no reason to believe they would not also work well on all game in the lower 48.

Most hunters and guides will recommend at least a 300 gr. bullet for grizz. There is no need for a hard cast bullet heavier than 300 gr in a .44 mag revolver. It's true that you can get more penetration with the heaviest bullets shooting maximum loads, but you can get more than enough penetration to shoot all of the way through an animal with 250 to 300 gr bullets. If you need to shoot through a grizzly and a moose standing side by side, use the bullets over 300 gr.

You can get about 100 fps faster velocity with a max loaded hard cast than with a max loaded JSP of the same weight. If the JSP expands at all, it will penetrate less than the hard cast. But the JSP can penetrate all the way through on elk and deer and it can reach the vitals and break bones on black bear and grizz.

For the largest Alaskan brown bear, a lot of Alaskan guides say any load in a .44 mag is inadequate even though heavy hard cast bullets are capable of penetrating completely through the bear or penetrating deeply enough to reach the vitals. I have no experience in this area. Ask some experienced guides who have done it or seen it done before.

USSR
August 15, 2011, 09:15 AM
But what about slow and normal - that's my question. Like something approximating the original 250 Grain .45 Colt load with a good, hard bullet that has a wide meplat?

The above mentioned load would be good for deer, but I would want something more for dangerous game. Personally, I would have no problem going after anything short of the big brown bears, with my 25-5 loaded with 280gr hard cast SWC bullets at 1050fps.

Don

reppans
August 15, 2011, 11:09 AM
Well, I'm no expert in firearm ballistics, but I believe the physics formula for kinetic energy would apply here. From what I understand, penetration is ultimately pure friction, and assuming we are talking about the same bullet frontal area (ie, same caliber, same ball or hollowpoint ammo), then my guess is that the pure kinetic energy number would determine the penetration depth.

The formula for KE = 1/2 MV^2, where M=mass and V=velocity.

The interesting thing here is that increases in mass will increase KE in a linear fashion, while increases in velocity will increase KE in a curve (a square function). So, for example, if you double the mass KE will also double, but if you double velocity, KE will quadruple; triple M = triple KE, triple V = 9 x KE.

Put another way, doubling the mass of a bullet should have the same effect as increasing the velocity of the bullet by 41% (ie, 1,000 fps to 1,410 fps) or 2^0.5 (sq rt of 2) = 1.41; a 50% increase in mass is equivalent a 22% in increase in velocity or 1.5^0.5 = 1.22.

Well, that at least gives an idea of what the relationship between weight and velocity it should be - obviously, increasing both helps. I have no idea what would be adequate for a large four-legged animal though :confused:.

CraigC
August 15, 2011, 12:44 PM
Leave the energy figures in the rifle forum. It is not applicable here, at all.

I have to disagree with the above that 250's penetrate as well as 325's. This is contrary to everything we know and Linebaugh's testing bears this out. The heaviest practical bullet for the .44 and .45 is 355gr and 360gr respectively. Extensive testing has proven that these penetrate the deepest but that going any heavier is detrimental. The question is how much penetration do you need? When Ross Seyfried took his custom .45Colt to Africa after Cape buffalo, he was shooting 360's, not 250's. One thing is very apparent in Linebaugh's penetration tests. Big, heavy, cast bullets with sectional densities in the .250-.270 range produce the best results, regardless of velocity. It has also shown that velocities over 1200fps do little more than flatten trajectory. There is no appreciable gain in penetration or killing ability by adding 200fps. However, there is a significant increase in recoil and muzzle blast.

goon
August 15, 2011, 02:03 PM
Ask some experienced guides who have done it or seen it done before.


My friend, that is exactly what I'm trying to do... lol.

It has also shown that velocities over 1200fps do little more than flatten trajectory. There is no appreciable gain in penetration or killing ability by adding 200fps. However, there is a significant increase in recoil and muzzle blast.

This is the kind of answer I'm looking for. Can you show me a source?
I'll be honest - I've got nothing in my area right now that would give a .357 too much trouble, but I'm curious about how much is too much and how much is "just right" as far as big bore defensive handgun loads (against dangerous North American animals) are concerned.

IIRC, the original .45 Colt load used 40 grains of BP and a 250-255 grain bullet and got something like 1,000 FPS. The charge was later cut back to make it more manageable and velocity ended up around 800 FPS. This is based only on what I've read. I haven't owned a .45 Colt Revolver for almost ten years and was not able to chronograph any of my loads with it when I owned one.
I agree that I wouldn't necessarily feel well-armed with a "mild" .45 Colt load against anything bigger and meaner than a black bear (I don't call anything pushing a 250 grain bullet at combat speed weak exactly, but comparatively speaking, it's not stout either), but is 1100 FPS with a bullet around 250-280 grains enough to penetrate through the vitals of a brown bear or moose?

CraigC
August 15, 2011, 03:09 PM
Start here and then begin collecting the works of Ross Seyfried, Brian Pearce, Elmer Keith and John Taffin.

http://www.customsixguns.com/writings.htm

http://www.handloads.com/misc/Linebaugh.Penetration.Tests.asp?Order=5

tipoc
August 15, 2011, 03:22 PM
I'll be honest - I've got nothing in my area right now that would give a .357 too much trouble, but I'm curious about how much is too much and how much is "just right" as far as big bore defensive handgun loads (against dangerous North American animals) are concerned.

Well first it seems you have to separate out hunting loads from defense against dangerous game loads, or at least recognize that there is a difference.

A hard cast lead SWC type bullet from a 44 Spl. or 45 Colt at about 900 fps give or take a bit will penetrate more than adequately for an angled shot on deer or hogs. Often the round will go through and through, breaking the bone it needs to and leaving a good blood trail for tracking if that is needed. This will be true out to a distance that the shooter can hold for. Bullet type in important here.

This has been the case for over 100 years. Elmer Keith and others have written extensively on this.

For defense against dangerous game you want a load that you can shoot well at speed.

The question of what is "just right" is up to you. It's a question of what you can shoot well.

tipoc

goon
August 15, 2011, 06:22 PM
For clarification - I'm not worried about hunting loads. I'm trying to figure out what's needed to reliably penetrate to the vitals/CNS of a large dangerous North American mammal (like a brown bear or moose) and stop it from mauling, biting, stomping, or otherwise mutilating a human being.

And I get the point about what the shooter can handle comfortably and get back on target with, but there's got to be something resembling a minimum standard between "yep, you'll probably be OK with that" and "Nope. just carry a .22 and shoot yourself with it before the moose stomps you."
So I'm trying to kind of figure out where that line is... from an academic standpoint for now. Although at some point it might become practical knowledge.

I'll get to work looking up the sources you all mention as time permits - Seyfried, Keith, etc...

Mike1234567
August 15, 2011, 06:31 PM
goon...

I posted a similar thread just a couple days ago but mine was regarding "lowest prices" for high quality heavy-weight cartridges for protection against black bears and 400 pound boars. Of the many suggested rounds I opted for 300gr/1150fps JSP from Georgia Arms. Partizan has a similar offering. You can get heavier bullets but these are only 60 cents per round and, according to everything I've read, they're plenty effective against black bear, large hog, and even brown bear.

Here's the thread; Big Bullets With Little (okay, "reasonable") Price Tag (http://www.thehighroad.org/showthread.php?t=608497)

tipoc
August 15, 2011, 07:44 PM
For clarification - I'm not worried about hunting loads. I'm trying to figure out what's needed to reliably penetrate to the vitals/CNS of a large dangerous North American mammal (like a brown bear or moose) and stop it from mauling, biting, stomping, or otherwise mutilating a human being.

Well we already know that any load for hunting will...

reliably penetrate to the vitals/CNS of a large dangerous North American mammal

and we know that a 200-255 gr. bullet of hard cast lead, especially with a large meplat or swc type at close to or above 900 fps will reliably penetrate or that a 158 gr. or above load at 1100 fps and above will do the same we can say that those are good places to start.

But...

(like a brown bear or moose) and stop it from mauling, biting, stomping, or otherwise mutilating a human being.

and here all bets are off because even rifle rounds may not do this even with a Black Bear. Even the most powerful handgun rounds will not "reliably" do that and it is iffy with a rifle. Black bears have been known to take hits to the head with a 44 Magnum and not stop if determined and multiple hits to the body and not stop. They have also been known to drop from the same. This is also true of Brown Bears.

I'm surprised you ask this question because you seem to know the answer already from what you are asking.

If you are curious about this get a gun in 454 Casull. Over time try various loads and bullets for it (a good bullet that will penetrate deeply) and see which you can shoot rapidly and accurately. As such a gun will also handle 45 Colt you can always step down some. Take some time to learn what you can do.


And I get the point about what the shooter can handle comfortably and get back on target with

That is the point. You already know that the 9mm will not do the trick nor will the 38 Spl., except with more luck than you want to rely on. The power you are looking for begins with the .357 Magnum and the heavier loads for that. The 10 mm, 41 Mag., 44 and 45 Colt will do as with anything above those. The more power the better. But it is most definately a matter of the shooter. A 300 gr. pill at 1300 fps is useless if the shooter cannot handle it.

Only practice and experimentation will let you know what you can do. So here do as I do and go shoot some. Less internet babble more shooting.

tipoc

Pyro
August 15, 2011, 07:48 PM
I love what Buffalo Bore has been doing with their line of defensive ammo of just making hard cast wadcutters in every revolver caliber available.
Seriously, a .44 Magnum hard cast wadcutter or a .45 Long Colt hard cast wadcutter.
A heavy bullet with large meplat, moving actually quite fast. Even their 38 Special wadcutter has been proven to be an absolute cannon ball which moves quite quickly for it's weight.

goon
August 15, 2011, 08:02 PM
I guess if I ever find myself in the situation where I need one, my best course of action might be to invest in a pump action 12 gauge loaded with slugs or a Marlin .45-70.

481
August 15, 2011, 09:11 PM
But what about slow and normal - that's my question. Like something approximating the original 250 Grain .45 Colt load with a good, hard bullet that has a wide meplat?

BTW - thanks for the link to Garrett's site. It was educational.

Well, if you wanna use a .45 Long Colt 250 gr. HCSWC/LFN as an example and define "normal" as having a velocity in the 850 fps range (it seems like most of the manufacturers have setlled on 850-ish as a "normal" velocity for that bullet weight from what little I've seen in ammo catalogs) depth of penetration in soft tissue can be predicted using MacPherson's equations.

In that case, you can expect ~32.5 inches of penetration. (and somewhat less if you hit bone depending on its properties)

Double Naught Spy
August 16, 2011, 01:03 AM
One easy way to test penetration is to shoot into wet newspaper. Randy has done this, and has some anecdotal evidence on his site; the way he puts it, "the faster they are, the faster they come to a stop."

But as the faster round deccelerate to the speed of the slower rounds, should they then not penetrate more deeply? LOL.

I think what he is getting at is that there is a velocity sweet spot or sweet spot range for a given set of parameters to achieve what you want to happen. Too much or too little and you won't get the desired results.

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