Googling has yielded nothing but confusion so here I am. Looking for a .338 30/06 length cartridge, I have been looking at these two but, it is unclear to me if they are exactly the same or, what difference exists.

Or put a different way, if I buy a used 338/06 AI how do I know if it is safe to shoot loaded 338/06 A-Square? I get one is SAAMI and one is a wildcat but, it seems pretty standardized. I guess I could always buy a rifle and cut a 1/4" off and rechamber with an A-Square reamer but, that seems pretty wasteful without any other reason to clean up the chamber.

And no, I have no love for a 325 WSM. Separate from WSM brass, 8mm reloading options are not what I want. A 338 WM is also redundant (more so) as I have a 358 Norma Magnum if I need a bigger boomer for something like Elk or an Alaskan bear.

TIA,
Sid