Check out Rhino Bullets. In their site they cite heavy H&H bullets stopping a wee bit better. I think it's just rhinobullets.co.za

Rhino now has a 380-gr 375 bullet. According to PH Kevin Robertson in this month's The Accurate Rifle, heavier 375 bullets loaded to moderate velocities (2200)are far more stable at close range than overstabilized 300-gr and provide a LOT more wallop.