From my checking of handloading data, the .338 Mag and the .338-06 are roughly equivalent in performance. (100' /sec difference with 250 Gr bullets and equal barrel length per Hornady' s latest data)

I' d never build a wildcat that offered me no advantage over a standard factory cartridge. But often times the advantage falls in other arenas such as weight of the rifle, magazine capacity, cost and who knows what factors an individual may have.

Everyone has their own set of values and I certainly am two thumbs up on the .338-06