If your casting/buying the bullet I think your talking about, I cast the same from an RCBS mold. It should take care of anything short of large bears (grizzly,brown). That bullet seems to be accurate in my SRH butI do get some leading,but that problem is because of a slight restriction where the barrel is screwed it to the frame. IIRC they dispatched cattle with the standard 250 gr load so I ould be comfortable with the 270. Which pistol do you plan on firing it from?