Ok...I have this really nice 300 Ultra-Mag, but it is not what I want. Remington came out with the 300....then they made a 7mm, a 338 and a 375 Ultra-Mag....but I want a 350. Has anyone heard of any such custom chambering? I want one. The 7mm, 300 and 375 are all long action, but the 338 is a slightly shorter case, why?, I don't know. But where-as I think the shorter 338 case is enough for my needs...I already have the long action so might as well take advantage of the larger case capacity. I do not have a clue why they missed .358 caliber...I guess it is due to the myth of better bullet selection in the 338. Let's build a rifle.