My current project is to build a 35 Whelen for hunting. My plan is to load up 225-grain Barnes copper bullets ( or maybe as light as 220, or as heavy as 250) for this. The Barnes copper bullets are longer than the equivalent weight of lead bullets, so I suppose the twist rate should be faster than if I were shooting lead. What twist rate do you think would be best? 14": 1 ? 12":1 ? Your input would be appreciated.