Originally Posted by ldmay375
I have no idea what the actual contours of the M70 Super Express at 22" and the Mark X / Whitworth at the near 24" equate to, but I like them both for a general purpose rifle. The Mark X / Whitworth may eventually receive a trim to 22 or 21".

I think the barrel contours for the Winchester 375 H&H Safari Express and stainless classics also are more appropriate to 458's. Though not too shabby in .416.

Edit = I fully agree on the 1-10". No idea how that would do with hard-cast powder coated bullets ??

Sir Larry,
I will be able to try some heavy cast bullets at low velocity in a 1:10" twist .458 soon. Fingers crossed.
But the 1:10" will be forgiven if no good with cast, due to its special purpose utility.
Certainly 1:14" is the best all-around twist for a .458 WM.

The M70 Super Express .458 WM is pretty close to a No. 5 Sporter contour, but so are the .375 and .416 M70 factory barrels.
Good on the .458, but a bit heavier with the smaller bores, aye.
The Whitworth is closer to a No. 4 Sporter at the muzzle on the .458 but is a bit beefier closer to the breech, nice contour for balance.
Again, same profile on the smaller bores makes them heavier.
CZ 550 Magnum is close to a No. 4 Sporter for .458, .416, and .375.
Winchester, Whitworth, CZ all have their departures somewhere between breech and muzzle,
differing in their tapering and swelling from the the more standard barrel maker contours.

Super Express compared to Whitworth, photos:

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Ron aka "Rip" for Riflecrank Internationale Permanente
NRA Life Benefactor and Beneficiary
.458 Winchester Magnum, Magnanimous in Victory
THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.