Every one say that caliber .416 is the best penetrator but a 410 grain bullet in caliber .416 only have a SD of .338 and a caliber .458 have a SD of .375 with a 550 grain bullet.

I think that caliber .460 Wby will have the best penetration if you use 550 grain bullets.

What do you think guys...?

They are close but the 458 with a 500 gr. bullet at "equal speed" will out penitrate the 416 with a 400 gr. bullet, it will knock a bigger hole and it kills better...big dog gets the bone syndrome..Take that to the bank with you...

All that said, I have found the 416 and 404 capable of everything that I have asked of them.

I think it depends on what you are trying to penetrate. Ackley showed how a 220 Swift bullet would go thru armor plate like it was butter...whereas the /06 with AP bullet only chipped the surface. .224 vs .308 But for hunting purposes I suspect it will be as Atkinson says...the biggest heaviest bullet wins, assuming they are in the same velocity ball park. JMHO

Overkill

There are some 600 grain bullets in 458 aswell. They will penetrate even more, just hang on to the gun
Shoot placement is also very important

/ JOHAN