My Serria manual has 7 different powders for the 300 gn. bullet and they are listed up to 1,500 fps in a 16 in. barrel. My favorite powder for big heavy bullets in handguns is Win. 296 so here is the loads for it. Starting load is 18.6 at 1,300 and max. load is 21.5 at 1,500. You can load H-110 to these same charges and velosities. I would guess that you will lose abt. 100 fps per in or abt. 200 fps. , but 1,300 will still have alittle punch left.
