9Three,

Thanks for correcting me on the 870 blunder. I have never owned a Remington pump or semi-automatic rifle, but I did sight one in for a friend once and have never in my life felt more punished, shooting off the bench.

The twist issue dates back to the .250 Savage vs. .257 Roberts and the .243 vs. the .244, in both cases Remington looked at the .257 and the .244 as varmint cartridges and selected the twist suitable for for lighter bullets.

No explanation for the .35 Whelen twist, however.

On the other hand, the twist used by Winchester for the .458 is far faster than needed.