Caliber discussion

[Coercionist]

Recently I have wanted a ballistic hot rod and was initially looking at the Cheytac case however after consideration I have decided that the level of power the Cheytac outputs is not required for my situation. I want my rifle, based on either 30-338 lapua imp or 300 norma imp, to have a switch barrel lug allowing for me to swap in between two barrels: one for matches and tager work out to 2000 yards with some elk and moose (heavy .30) and then another caliber, on the same case whether it be, Norma or Lapua, in 375 for large game (African plains game and big bear). I would go for the increased power of the lapua case but I am wanting to mag feed this rifle. From what I have read the norma imp 35* from a 30" barrel can push a 230gr berger at 3100 fps. Ive also seen that the lapua can push the same bullet at about 100 fps faster. This is appealing given that i want to use the 245 Berger and the 250 A-tip. But would I be able to use any DBM? I read that in 2016 Ryan pierce spoke of a 4" dbm to be made by Curtis custom however i cant find it. Any data on the improved .30 cal cases (norma or lapua) or data on the 375 version of either would be extremely helpful.

TLDR:
Need info on the differences between the 30-338 lapua imp and 300 norma imp. Also looking to neck up the case I end up using to 375 for big/dangerous game, so also data on those wildcats, especially the 375 norma imp because I have zero data on it.