Re: 338-8mm Rem Mag
Has been done quite a bit since the late 70's. What you get is a 340 wby with cheap remington brass. It is a very good cartridge well capable of 1000 yard hunting. It shoots on average about 100-150 fps slower than the 338-300 ultramag or edge, 338 RUM and 338 Lapua.
Predictions are difficult, especially when they involve the future