500grains,

Not all of his loads are the hard cast Hammerheads, he's now making .45-70 loads with 350 gr. and 500 gr. Woodleigh Weldcores (the 500 gr. Weldcore at 1600 fps is mentioned as suitable for Cape Buffalo).

The other new load uses "the amazing 500-grain Speer Tungsten Solid and is recommended for use against elephant, rhino, and hippo." This load is listed at a velocity of 1530 fps.

I copied the maker's recommendations off of the product descriptions on the website.

Richard.