hand loading the 30-378 Why mag

My best load is with Barnes TSX in 180 grain with 107.5 rl25 and a 215m primer the Hornady manual says your c.o.l. for those 212's is 4.0 they'll fit in there but you'll have to pull the trigger or the bolt to get them out, I've tried what works in mine with others and it doesn't work, I'm trying to find a heavier bullet that will shoot as well as my 180's closest thing I've found is max
load in a Berger 210 with 50bmg powder next move is to change my seating depth to see if I can shrink my groups up

Whats your H50BMG Powder charge? Thats if you do not mind saying.

111.2 grains of H50BMG with Federal 215m primer seated to 3.648, I have 4 more test loads loaded with seating starting at 3.675 and increasing by .040 each load ending up at 3.795 which is as long as I can fit in my magizine plan on shooting them next weekend along with some Hornady 220 ELD-X that I just loaded

Thanks! I appreciate it! Working on gathering data for a build and all I can get help. Thanks.