If you can get the permits needed get a ruger single action in .45 colt Get a 300 gr mold and cast up some hard bullets. Put a bit of ww-296 under them and I gauruntee that will get the attention on a head shot of any bull at close range. Those heavy .45 bullets worked wonders for me on our larger critters over here. And the long bullets are wonderfully accurate too. Pretty stout recoil for your end too though.