Achieving the best penetration with .458 diameter rifle cartridge

[Colden]

Comparing Garret Cartridges Hammerheads with various dangerous game 458 Magnum and 458 Lott loads, it seems that the heaviest bullets available are somewhere around 500 gr.

This article (http://www.garrettcartridges.com/penetration.asp) claims that for a given weight (around 500gr) penetration actually reduces with extra speed. Here is a quote:

Very interestingly, if one takes the Hornady 500-grain .458 diameter solid bullet and compares the penetration that results from impact speeds varying from about 1500-fps to 2500-fps, one finds that the higher impact speeds produce the least penetration. When driven to about 1500-fps (as the 45-70 will do) one finds that such solids produce nearly 6-feet of penetration in wet newspapers. When the same bullet is driven to about 2100-fps (as is characteristic of the 458 Winchester Magnum) one finds that the penetration is reduced to about 4 to 4 and 1/2 feet. When one tests the same bullet at 2300-2400 fps (as is characteristic of the 458 Lott) one finds that the penetration comes up nearly 20% short of that produced by the 458 Winchester. And when one tests the same bullet at the blistering speeds characteristic of the mighty 460 Weatherby Magnum, one finds that the penetration achieved is the most shallow produced by the various 458s.

Is this true? If so, it may mean that a Marlin 45-70 lever rifle with the Garret's 540gr 1550 fps load is a better choice with milder recoil than the comparable 458 calibers. Is this basically the best combination of penetration without the need for expansion that one can achieve... short of a much heavier bullet with insane recoil? Seems to be a much cheaper route, too. What am I missing here?

Perhaps this is only true if the test is limited to a homogeneous medium (such as wet newspapers) and does not involve penetration through solids, such as bone?

 

[Colden]

More quotes to consider

Taken from Garret Cartridges' web site:

Does the 540-grain Hammerhead Ammo actually out-penetrate the 458 Winchester Magnum and 500 Nitro Express when using solids? Yes, as was demonstrated for all to see at a recent John Linebaugh seminar. The penetration results, which parallel ours, demonstrated that the 458 Winchester Magnum produces 47-inches of penetration in wet newspaper with 500-grain roundnose solids and that the 500 Nitro Express produces 48-inches of penetration in wet newspaper with 570-grain roundnose solids. By comparison, our 540-grainer with its super blunt front end produces an impressive 55-inches of penetration in the same material. Nearly 20% deeper penetration than the 458 or 500 Nitro Express with roundnose solids!

Very interesting, if independently verified as true. Marlin is the only rifle they recommend for this load. I guess the question remains, is a Marlin 1895 or 1895G (or GS) reliable enough to use with dangerous game? It's not a controlled-feed bolt action, after all.

 

[Preacherman]

I'm moving this to the Hunting forum, where members are likely to have much more experience in penetration of big-game rounds.

 

[DigMe]

Very interesting, if independently verified as true. Marlin is the only rifle they recommend for this load. I guess the question remains, is a Marlin 1895 or 1895G (or GS) reliable enough to use with dangerous game? It's not a controlled-feed bolt action, after all.

I've never hunted dangerous game but NO WAY would I used any of the common lever guns for that. Chances are everything would go fine but I just don't think I would have confidence that I'm going to get a positive extraction every time. And don't get me wrong...I like lever actions and sometimes hunt with a Marlin .30-30.

brad cook

 

[Art Eatman]

As for the penetration comparisons, I'd guess that the higher velocities would or could see more deformation of the bullet. Deformation, seems to me, would reduce its travel.

Safety? Doesn't the Garrett website talk about what guns are suitable? (Haven't been there; dunno.) PM Wild Alaska; I think he's got some experience with all that stuff...

Art

 

[redneck]

I think Rich Lucibella from thefiringline.com hunted buff in Africa with a .45-70 levergun. Seemed to do the trick.

I don't know if I'd do it or not.Personally, kind of like the idea right now (I am a redneck after all ) but don't know if I would stick to that choice if I ever actually went there.
Penetration is only one aspect. You only need so much penetration, once you got it you start concentrating on making the hole bigger. Seems like the other cartridges might offer a little expansion along with deep penetration.
You also have to question how realistic the test medium is. I think if you go back and read some posts by H&H Hunter, you'll find that his Lott would reliably go through a buff lengthwise. Wet newspaper might compare their penetration, but does it accurately show their performance in real life situations?

 

[Art Eatman]

Rich's African hunt can be found in the Hunt forum at The Firing Line. IIRC, he had a Guide Gun in take-down configuration. I think--but don't remember for sure--that he used Garrett ammo.

Art

 

[Matt G]

He also used Buffalo Bore. He found that the BB ammo didn't break up as badly. (Though Rich still speaks fondly of Garret ammo.)

 

[kudu]

Remember that these people are sponsored by Garret Cartridges, and that no two bullets tested were the same bullets. Yes it said they were 500grains, but were different designs. This was written to promote Garret bullets more than likely.

If they were to load identical brand bullets it would be a realistic test.

 

[redneck]

Good point Kudu
When I read stuff like this I don't really make any judgements on whether one thing is better than another. Mostly I think it just shows that .45-70 could be a viable choice for dangerous game. Not a better or worse choice, just that its an option. You still have alot of other variables to work out after the cartridge is selected. Have to be shooting a reliable and accurate gun, in a platform that handles well for the conditions and all that other stuff.

 

[Mannlicher]

What I think this shows, is that Garrett wants to sell its bullets.
I would have to see a lot more on this to believe that a premium Solid, would be our performed by a cast bullet. Their findings go against logic.
I have seen pics, and read, about solids being retreived from dead pachyderms, after traversing virtually the entire length, bones and all, and displaying almost no marks other than those of the rifling.

 

[Dr.Rob]

Even at its hardest, a hardcast should act JUST LIKE a solid... so what's the difference?

Garrett has a big metplat (flat spot on the nose) and the solids usually don't.

You would think that a bullet designed this way would penetrate less than a pointy bullet.

Garrett's stuff is certainly stout, but I don't think it's better than a 'real' African caliber.

That's just my opinion.

 

[Gordon]

Now this is an apples to oranges comparison! OF course higher velocity = greater penetration given equal weights AND A NON DEFORMING BULLET! The problem is that as bullets exceed about 1800fps it is HARD to keep them from riveting. And to add to the problem pointed bullets tend to tumble or yaw more than bluff nose ones. So sectional density, mass, and velocity are all multipliers of penetration depth IF the bullet remains undeformed AND point on after impact. Field testing has shown blunt nose monolithic solids or extremely reinforced jacketed slugs CAN be made to hold up to HV impact on animals and drive straight. However an increase in diameter of a projectile that penetrates to the desired areas increases the disabiling effects. So SOME 'riveting' of a long heavy slug is actually desireable as long as it has more than adequate penetration of the desired target.

 

[Yooper]

The above quote mentions "the same bullet" being used at various velocities to produce results in wet newspapers. I don't know what physical principle is at work here to indicate less penetration at higher velocities other than bullet deformation. Wet newspaper lacks the elasticity of muscle tissue, but as long as it is a constant for the experiment it seems valid. The meplat of the projectile compared to pointed bullets could be correlated to flattening the point of a finishing nail to prevent thin wood from splitting when the nail is driven. It tears the wood fibers rather than separating or splitting them. I think John Linebaugh did some penetration testing at one time. Elmer Keith tested penetration in "imitation bear muscle", but that was an apples/oranges comparison to prove his point about certain handgun bullets penetrating better than certain rifle bullets. I wonder if anyone has done any objective penetration tests using several cartridge/bullet combinations.