Which caliber over .458

Bruce said:

Agree with IvW here...years ago my PH in Tanzania used a 500 Jeffries... absolutely amazing rifle.
I personally use a 458 Win Mag, BUT imI not a PH...YET!!!

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IvW told us, a .458 Win-Mag is not capable of punching a dent into a traffic sign....



HWL

HWL said:

IvW told us, a .458 Win-Mag is not capable of punching a dent into a traffic sign....



HWL

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LUCKILY, I don't hunt traffic signs with it...only buff and elephant!!!

IvW said:

That is only a mathematical formula and not a true reflection of actual performance in the field. As soon as what ever you have calculated the momentum for encounters something in it's path the whole formula changes. The heavier projectile will outperform the light one.

AxB=C but this does not kill whatever you are shooting at, shot placement penetration and proper bullet design does.

Certain bullet designs out penetrate others eg. meplat solids (and the new design convex solids) of the same weight @ the same velocity will out penetrate round nosed solids.

The bullet design creates a "cavity" ahead of and around the bullet creating less "skin" drag on the bullets outer surface which in turn makes the bullet penetrate deeper.

If you now however increase the velocity too much you destroy the cavity and the bullet again encounters increased drag from surrounding tissue which decreases its penetration. It is called supercavitation.

The sweet spot is between 2200 and 2400 fps for big bore calibers.

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IvW, it’s a rare and happy moment to meet a man who understands the difference between cavitation and super cavitation. I agree whole heartedly with you but did feel the need to add to your explanation as it leaves open a logic trap I have seen many fall into before.

When the bullet is undergoing super cavitation it will slow down and pass through the suggested ideal speed. This causes many people to think it will then go into the cavitation and penetrate farther than the one that started in the cavitation regime. However by this point the bullet is normally undergoing some amount of yaw from the unstable flight during the initial super cavitation, so it is not longer capable geometrically of the cavitation. And thus less penetration if your initial speed is too fast.

There is a caveat in that changing the shape of the front will change the speed at which the different cavitation regimes exist so it would be possible to make a bullet that will stay in the proper regime for say a 460 weatherby, but to my knowledge no one makes such a bullet. And of course for round nose solids with no deformation all of this is moot, more speed with that bullet will lead to more penetration.

I do have a slight problem in your earlier message where you said momentum suffers. It doesn’t as it is merely a mathematical construct. Penetration suffers for sure but not momentum.

And as a last note cavitation is also highly dependent on the bullets spin speed, and the viscosity and Young’s modulus of the material the bullet is traveling through but that becomes a largely academic discussion with negligible real world application

Question would be: Why do you want bigger (besides because I can)? If it was me I would stick with the 458 cal and look at a 450 Rigby (which I have). A 505 would be nice, and for what the heck's sake a 577 Tyrannosaur, but the 450 Rigby will kill things just as dead.

8x68 said:

Question would be: Why do you want bigger (besides because I can)? If it was me I would stick with the 458 cal and look at a 450 Rigby (which I have). A 505 would be nice, and for what the heck's sake a 577 Tyrannosaur, but the 450 Rigby will kill things just as dead.

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Why do people want to shoot a white tailed deer with a 30-06 that has a foot pound to weight ratio of 15 to 20 times and then for some reason have a problem when someone wanting to shoot a cape wants something bigger than a round that offers a bit more than a 458 that offers a foot pound to weight ratio of maybe 4 to 1?

From a PH point of view there is a big difference in stopping ability between a 500 Jeff and a 458 WM or Rigby although the Rigby is quite good.

Von S. said:

Why do people want to shoot a white tailed deer with a 30-06 that has a foot pound to weight ratio of 15 to 20 times and then for some reason have a problem when someone wanting to shoot a cape wants something bigger than a round that offers a bit more than a 458 that offers a foot pound to weight ratio of maybe 4 to 1?

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IvW said:

From a PH point of view there is a big difference in stopping ability between a 500 Jeff and a 458 WM or Rigby although the Rigby is quite good.

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Valid points. To each his own I guess. All depends on the shooter and ones ability to shoot effectively.

Well sure 8x68,

I have never cared what anyone has ever used for anything.

Give me the choice between hitting something big, smelly and ill tempered and I will take the one that hits with 6 tons of energy compared to 2 tons any day of the week.

Maybe one of the reasons why so many say that capes are so tough to bring down is because they aren't being hit with enough power to begin with?

Your normal milk cow weighs on average a few hundred pounds more than a cape. A big male moose can go 1500 pounds, and a Florida swamp hog is normally about 100 to 150 and I have seen all 3 run away after being "shot right" with the 375. My one friend drilled a big moose 3 times in the chest with his ,375 and he started wondering if he missed it. I told him he hit, but he wasn't convinced so he asked me to shoot and at around 125 yards I shot him in the neck with a 350 expanding bullet and he fell over.

My friend had indeed hit him 3 times in the chest with pass through shots and my guess was that the moose was just standing there dead.

I've seen multiple hunting video's of Cape Buffalo hunts. They have been shot with a multitude of calibres. Most shots were good, some not so much to the chagrin of the PH. Yes CB's are tough but any animal that wants to live can make things "interesting" no matter how well the shot was or how much "tonnage" it received. Agreed sometimes bigger is better but not always.
One of the guys I shoot with had the same situation happen to him. Swears he smoked a moose at about 300yds but it wouldn't go down. When they got up to it it was dead but propped up by a small tree that could not be seen from 300yds away even with a scope. It had 3 shots all within a 3" group, and all in the boiler room!

8x68 said:

Valid points. To each his own I guess. All depends on the shooter and ones ability to shoot effectively.

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Agreed.

If you have the same shooting ability with the 500 Jeff(or the 505 Gibbs) as you have with a lesser caliber the effects will be so much more devastating and effective.

Often you do not have the ideal shot presentation when the chips are down and that is when the extra ability/power/penetration of the larger cartridge can save your bacon or your tracker or clients.

8x68 said:

I've seen multiple hunting video's of Cape Buffalo hunts. They have been shot with a multitude of calibres. Most shots were good, some not so much to the chagrin of the PH. Yes CB's are tough but any animal that wants to live can make things "interesting" no matter how well the shot was or how much "tonnage" it received. Agreed sometimes bigger is better but not always.
One of the guys I shoot with had the same situation happen to him. Swears he smoked a moose at about 300yds but it wouldn't go down. When they got up to it it was dead but propped up by a small tree that could not be seen from 300yds away even with a scope. It had 3 shots all within a 3" group, and all in the boiler room!

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My north of the border brother,

Here is where I must disagree.

Bigger, badder, faster, stronger is BY FAR always better for killing anything and being a player in the NFL.

My personal opinion is that the 375 H&H might just be a bit underpowered for a few of the dangerous game animals. Hell! I believe that the 458 WM is at the bottom shelf of acceptability.

"If" I am up to it my next and last trip to the big A I will bring a 378 and the T-Rex or maybe the Over Kill.

By the way, "she who must be obeyed" has had some words of wisdom for me that sound like they came out of " One Flew Over The Coo-coos Nest" about me hunting in Africa.

"What do you want to do? Die over there?"

"If you die there, plan on staying cause I'm not coming to get you!"

Poor thing, my Norwegian Ice Princess is now about as sharp as a beach ball.

Grasping all the concepts and mathematics is evidently over my head. I'm mostly directing my question to IvW.
Please explain to me in "kindergarten" terms what happens to the extra energy created by a 500 gr. out of a .460 Weatherby compared to the same bullet out of a .458 Win. My inquiry is sincere since I have no working knowledge about the "cavitation actions" being referred to.
Layman terms please.....

Thanks for your replies, Bob

Bas said:

Grasping all the concepts and mathematics is evidently over my head. I'm mostly directing my question to IvW.
Please explain to me in "kindergarten" terms what happens to the extra energy created by a 500 gr. out of a .460 Weatherby compared to the same bullet out of a .458 Win. My inquiry is sincere since I have no working knowledge about the "cavitation actions" being referred to.
Layman terms please.....

Thanks for your replies, Bob

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The extra energy goes into friction. Cavitation means it is creating a small air pocket around the bullet so it has friction with air and energy goes into damaging the tissue. Without the cavitation the bullet has more direct contact with the tissue so it expends energy on tissue damage and friction.

Lbarr265 said:

The extra energy goes into friction. Cavitation means it is creating a small air pocket around the bullet so it has friction with air and energy goes into damaging the tissue. Without the cavitation the bullet has more direct contact with the tissue so it expends energy on tissue damage and friction.

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Thanks for your reply lbarr, Bob

Papabear55 said:

Is it just because the 500 jeff is moving about 200 or 300 fps faster? Would it be feasible to increase the 500 nitro's velocity by that much or close to it using the right propellants in a suitably strong action?

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I am late to this party , something interesting about the .500 Jeffery...it is a big bore rifle capable of excellent accuracy out to 250 meters...I do not know any other heavy weight caliber that can achieve this .

The 12.7 x 70 Schuler is an excellent round , and though it is one of the best it does not carry the distinction of being the best.

I spent a few hundred dollars on brass pills and dies for 505 gibbs cause it was a good deal and i couldn't pass it up, Still don't have a rifle yet. I'm waiting to come across a used cz 550 one day or break down and order one.

D.M.V said:

I spent a few hundred dollars on brass pills and dies for 505 gibbs cause it was a good deal and i couldn't pass it up, Still don't have a rifle yet. I'm waiting to come across a used cz 550 one day or break down and order one.

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I like the way you think

Ya i got everything for 200$, the die set alone cost that much, 80 pieces of brass and 100 or so bullets.