Google is your friend .... it pointed me to the correct spot on the Lyman site.
The beast holds up to 6lbs. of media (or fill to 1/2 - 3/4 full of media) and up to 315 30.06 shells .. so if your shells are a little larger, adjust accordingly. I would hazard a guess that it will hold all of your 338 Lapua brass and then some ..