bonanza50, be careful with reccomended loads for the 375 H&H belted magnum in your DOUBLE RIFLE! The S/S double rifle is not the place to go experimenting with loads when chambered for cartridges like the 375 H&H BELTED MAGNUM! The loads Ray gave you are for bolt action rifles, it is well known he will not own a double rifle chambered for a high intensive cartridge like the 375 H&H B.M, or 416 Rigby. Both are in the 45,000 to 60,000 psi range with common hand loads, and even some factory are too hot for doubles. IMO a 375 H&H Belted Magnum should be kept in the loading not to surpass the loads for the 375 H&H flanged. Also do not use monolithic solids in the double. Your best bet is a load for the flanged 375, with the 300 gr Woodliegh softs, and solids, useing a 375 H&H flanged loads worked up till they regulate! Though your rifle was made today, it is still 17th century technology, and will not tollerate the high pressures of a bolt rifle, for long, if at all!