It would be either a C-.375 or a D-.400. You could probably use either. The cross section they have listed for saami is .3963 which is in between both of C&D.
Awesome, thanks guys. I ordered the .400 gauge and it worked perfectly. Come to find out I was bumping my brass .012 which was leading to case separation at around 5x firing on the brass. Because of this handy little gauge I am able to dial in a .0015 bump -- thanks again for the help!