sectional density, penetration, and .357 vs. 44

[roscoe]

A recent thread in the handgun forum discussing the best round for grizzlies (again!?:http://www.thehighroad.org/showthread.php?t=129305) referred to the fact that the .357 might have better sectional density than the .44. This got me wondering:

a. whether this is true, and

b. does this make the .357 better for hunting something with a lot of thick hide, muscle, and bone?

Is it possible to get a heavy .357 round going fast enough to penetrate better than the .44? Just for comparison, Buffalo Bore has a .44 +p+ that is 340 grains and goes 1400 fps from a 5" pistol, while the 180 grain .357 gets almost the same speed at 1398 fps. Granted, these are extreme performances from the rounds. In particular, the next best .44 cartridge from BB is 305 grains at 1325 fps.

Does that give the .357 better penetration? Does it also mean less drop?

That being said, I understand the point about a big hole being better, but I am intrigued by the idea that the .357 can penetrate better than the .44 and might therefore be more effective in certain circumstances, assuming hardcast bullets.

I was in the market for a compact .44 lever gun, but this had me reconsidering.

 

[joshlm]

I am no expert on the subject but I would have assumed that of the two rounds you mentioned the 44 would penetrate farther due to the increase in bullet weight if the slugs were moving at the same speed.

 

[RyanM]

Assuming bullet shape is the same, more sectional density for a given velocity = more penetration (bullet weight is directly proportional to penetration, and bullet area is inversely proportional; doubling weight or halving area doubles penetration depth).

Buffalo Bore's heaviest .357 bullet is a 180 grain hardcast moving at 1,400 fps from a 6" barrel. Their heaviest .44 is a 340 grain hardcast at 1478 fps.

Sectional density on that particular .357 bullet is .202, while the .44's SD is .264. Not much of a contest there.

Sectional densities for common weights

.357
125 gr -- .140
148 gr -- .166
158 gr -- .177
170 gr -- .191
180 gr -- .202

.44
180 gr -- .140
200 gr -- .155
240 gr -- .186
275 gr -- .213
300 gr -- .233

 

[mete]

Forget the sectional density since bullet construction plays a big part . The 44 mag has been show ,by those who have hunted with both ,to be about twice as effective as the 357 mag !!

 

[jem375]

well, let's put it this way the 44 mag in Africa has killed elephants and no way would I want to try to shoot an elephant at close range with a 357 mag...

 

[shotgunner]

I've also heard that shooting pistol rounds through a rifle bring about entirely different ballistics. The velocity and energy substantially increase because of the longer barrel.
I'm no expert, but this is what I've gathered from the various posts and knowledgeable members of THR.org.

I'd get the .44mag in a levergun, as a matter of fact, here are the two that I'm considering.

http://www.winchesterguns.com/prodinfo/catalog/detail.asp?cat_id=534&type_id=094&cat=003C

http://www.marlinfirearms.com/firearms/leverActionCB_rifles/1894Cowboy-Othr.htm


I might go for the marlin, becuse of the +1 mag capacity and also I hear the actions are smoother. That Winchester Trapper sure is a looker though.

GL With the decision and safe shooting!

 

[rockstar.esq]

Go with the .44 mag and don't look back! They may not be as glamorus as sleeker, faster, or more "High tech" calibers but they hit like a bolt of lightning and give all the accuracy you'll likely need. Plus if you get a lever gun, you can load it with .44 spls and shoot it plenty!

 

[Brasso]

Given equal sectional density, which can be achieved with .357 and .44 cartridges, guess which bullet will penetrate farther? Yep. The heavier one.

 

[munk]

Given equal sectional density, which can be achieved with .357 and .44 cartridges, guess which bullet will penetrate farther? Yep. The heavier one>>>>>>>>> Brasso

Do we know this to be true? It's logical. But even with bullets of identical construction, I wonder. I remember first hand accounts of African cartridges, specifically how the 375 penetrated better than larger, more powerful cartridges. The 41 penetrates better than the 44 in some cases, (though if a 41 250 penetrated as good as a 44 300 I'd be a little suprised)

I'm just wondering if there aren't other physical factors involved. Speed relative to diameter might be one. And it might be that given the range of general mag velocities, even with equal sectional densities, the larger round might not do as well as expected, it's weight not enough to overcome diameter within the range.

I am only trying to question anomalys, not that the 357 is superior to the 44. It isn't. Yet there are professionals who use them.

I am wondering why certain cartridges, both rifle and handgun, perform better on game than the math can predict.


munk

 

[Cosmoline]

Ryan, you left off the 200 grain .357, with a SD of about .223

That said, while the .357 leverguns are impressive the .44 Magnum versions are even more impressive. In leverguns I'd go with .44 Magnum for more power. Recoil will still be on the mild side in a Marlin.

 

[Brasso]

I'm sure velocity does have a great effect on penetration, especially with hard cast lead bullets. However, with equal sectional densities and velocities, the .44mag will stomp the .357 in penetration. Given the stipulations above, the .44mag will have a bullet on average twice as heavy as the .357. That means twice the momentum.

I can't argue that a .375 can't out penetrate a larger caliber such as a .458. The 45-70 can be loaded close to 458 velocities, which is poking along pretty slow compared to a .375.

 

[munk]

I dunno. The 375 300 gr starts at 2600 max- longest and best barrel. Expect 2500 or even 2400.

I'm sure 'magical cartridges' can be explained by science. I just don't know the right questions to ask. There are reasons why some cartridges outperform expectations and others fall short.

I would also prefer the 44 to the 357 by a wide margin.

I wonder what would happen if the slugs were slowed down, say to 800 fps- would the 44 still outpenetrate the 357, or would the 357's smaller diameter perform better than the 44's fatter face?

munk

 

[RyanM]

I'm still 99.99% sure that equal sectional density and equal velocity = equal penetration. Only test data I can find is here. http://www.stevespages.com/page8f.htm

.44 magnum; 180 gr @ 1562 fps; .731" and 146.7 gr recovered; 17" penetration.

A similar .357 was a Cor-Bon 125 gr @ 1395 fps; .632" and 91.3 gr recovered; 17" penetration.

Another .357 was a Federal Hi-Shok, 125 gr @ 1432 fps; .530" and 63 gr recovered; 18" penetration.

.44; starting SD of .140, expanded SD of .0392, 17" penetration
.357 Cor-Bon; starting SD of .140, expanded SD of .0327, 17" penetration.
.357 Federal; starting SD of .140, expanded SD of .0320, 18" penetration.

If anything, that seems to indicate that the .357 is a better penetrator, since the recovered SD and starting velocity on both were both lower than the .44, yet penetration was the same.

 

[Cosmoline]

I think Ryan is right on the money. Penetration is primarily a product of sectional density and velocity. The weight of the bullet is already accounted for in the SD rating. The other major factor in penetration would be bullet shape and hardness, since a soft bullet may assume a rounder shape and have a decreasing SD as it moves through the animal (or whatever). Nose shape might also play a role.

 

[roscoe]

So, if the heaviest .357 and .44 rounds have comparable sectional densities, the question is which one can be made to go faster. I know that the .357 is well known to get a considerable boost from a rifle (500-600 fps in a 16" barrel); the question is whether the .44 does as well.

 

[Brasso]

I have to question a 125gr .357mag getting anywhere near 17" of penetration in anything. Not saying it isn't possible, I"ve just never seen it.

 

[BluesBear]

A .357 magnum shooting a 180 grain hard cast lead semi-wadcutter bullet at 1000fps will penetrate more than a .44 magnum shooting a 180 grain hard cast lead semi-wadcutter bullet at 1000fps.

The equality stops there.

 

[The_Antibubba]

I've been told by several sources that a .357 out of a rifle barrel 16" or longer approaches the MV and effectiveness of a .30-30. What a .44 out a rifle barrel, I've not heard.


OK, so SD is a factor, but isn't inertia a factor as well? If a heavier object is moving at the same velocity as the lighter one, won't it take more resistance to slow it down?

 

[BluesBear]

I believe that is momentum not inertia.

If both projectiles have the same (or similar) nose profiles then the heavier one will penetrate further if both are driven with the same velocity.

A 200gr semi-wadcutter travelling at 800fps will penetrate deeper than a 150gr semi-wadcutter travelling at 800fps if they are both of the same diameter.






However a 250gr full wadcutter driven at the 1000fps may not penetrate as deeply as a 125gr spitzer driven at 1000fps.