Yep, it's all about the power factor and heavier bullets are more efficient. Over the years I've gravitated towards heavier bullets. They just work better. More lead surface riding down the barrel, especially in the rifle. I think that the race towards lighter bullets has been a mistake. The only cowboy load that I ever had a"leading" problem with was the 160g in a 45. They're so short that there is almost nothing contacting the rifling. That's also why I shoot full wadcutters in the revolvers when I can. Good shootin'!!