What kind of velocity and powder were you using with the 350 TSX? I would think they would take a fair bit of room up in the case . My old 550 shoots everything great as well. Hopefully my AHR does the same.
64 grains of RL15 at about 2350 fps if I remember correctly, they do take up a lot of space but that is the beauty of the spacious CZ magazine and throat, seat the bullets way out and you have plenty of room