Accoriding to Federal Ammuntion the 200 grain Bullet for the 300 WM will drop 26.6 inches at 400 yds. The .338WM shooting a 210 grain bullet wikll drop 23.3 inches at 400 yds.

Foot pounds of energy:

.338 - 1828
.300 - 1551


Pretty close...but I still choose my .338 over all of them.