416 Rigby vs 458 WinMag a civil discussion

[CZDiesel]

There is a very recent thread where the OP was pondering between a 416 and a 458 and there were many that posted that the 416 will out penetrate the 458…
Now the OP had said that he posted because he wanted both feedback but also because it’s fun to have these discussions. So I thought I’d follow up along the same lines in that let’s keep it fun and informative!

So it’s interesting to me to hear some here say that the 416 will out penetrate the 458? I’ve never heard that before, doesn’t mean it’s not true though?
Now the 416 Rigby and the 458 WinMag are very close in energy but the 458 has better SD, better momentum, and a larger meplat… Theoretically this should all lead to not only more penetration but much more damage along the way?
In real use, not theory, my PH told me without hesitation the 458 WinMag, both Dalton and York of the very know Dalton and York Safaris use the 458 WinMag, Kevin “Doctari” Robertson calls the 458 the “Gold Standard”, and Taylor wrote in his book that while the 416 is a much better all around cartridge it’s not a stopping rifle where the 458 is?
Now in all of this penetration is key! So can anyone show where the 416 which has less energy, less momentum, smaller meplat, and less weight can out penetrate the 458?
Let the fight begin lol

 

[Badboymelvin]

Hi CZDiesel,

I have no experience with the 416 Rigby but have had a bit with the .458 Win Mag, having owned 5 and reloaded for all of them...

From what l have read, and from what l have been lead to believe, the problem with the .458 not penetrating sufficiently is when the expected velocity wasn't achieved.
When the desired 2150fps with a 500gn bullet was achieved l have never heard of anyone complaining of it's performance on dangerous game.
In fact, isn't 2150fps with a 500gn bullet the benchmark for DG?

When reloading for the .458 l have never had a problem reaching 2150fps with a 480-500gn projectile.
The highest l have reached with a 500gn projectile is 2220fps and this was from the 24" barrel of my Winchester M70.
I had a custom CZ550 in .458WM with a 21" barrel and l was still able to reach 2150fps with a 500gn Woodleigh. I did this by loading to suit the long magazine of the CZ and using a Lee FCD to crimp the bullet.

I also managed 2100fps with the 550gn Woodleigh and 2300fps with the 450gn Woodleigh Hydro in the .458 Win Mag.
I just can't imagine either of these loads lacking penetration and with modern bullets like the CEB that weigh less - but penetrate more, I could only imagine the .458 Win Mag being more effective than ever...

So l don't know if any of this helps at all but l guess what l'm trying to say is that it's not hard to reach 2150fps with a 500gn bullet out of the .458 Win Mag.
I've done it in all of my .458's I've owned and I'm a nurse - not a PH, so if l can do it anyone can...
And like l said earlier, l've never read of any complaints of the performance of a 500gn bullet at 2150fps on DG...

Russ

 

[Mark A Ouellette]

There is a very recent thread where the OP was pondering between a 416 and a 458 and there were many that posted that the 416 will out penetrate the 458…

Now the 416 Rigby and the 458 WinMag are very close in energy but the 458 has better SD, better momentum, and a larger meplat… Theoretically this should all lead to not only more penetration but much more damage along the way?

This could not be any more simple...

Example:
A. With 10 pounds (4.5 kilos) of force pushing a unsharpened pencil (flat surface/meplat .25" (5mm) diameter against their skin, will that penetrate (break the skin)? Probably not.
B. Try the same with a flat meplat shaft of .1" (2.54mm). Does the 10lbs pressure push the smaller diameter shaft through the skin? Maybe with a much better chance than the larger diameter shaft.
C. Decrease the diameter of the shaft to .05". Certainly that will penetrate all but the toughest skin.

If all else is equal such as energy and bullet shape and material, the smaller diameter bullet will encounter LESS resistance to it penetrating.

What I think you are not factoring into the results of dead dangerous game is that with equal energy, the larger diameter bullet will TRANSFER more energy quicker than will the smaller diameter bullet. That is part of Taylor's Knock Out Factor.

https://en.wikipedia.org/wiki/Taylor_knock-out_factor ​

The Taylor KO factor (TKOF) multiplies bullet mass (measured in grains) by muzzle velocity (measured in feet per second) by bullet diameter (measured in inches) and then divides the product by 7,000, converting the value from grains to pounds and giving a numerical value from 0 to ~150 for normal hunting cartridges. It is proportional to the momentum at the muzzle times the diameter of the bullet. Expressed as a fraction, the Taylor KO Factor is:

TKOF = Mass x Velocity x Diameter divided by 7000