First of all your going to have to try out different brands until you find one that shoots well from your rifle. Every rifle will shoot differently and by the way every brand and type of bullet doesn't preform perfect every time. Core-lokts are excellent bullets and have probably taken more deer then just about any other on the planet. 3'' in my opinion is not acceptable so start trying for better, the winchester powerpoints will kill a deer just as fast. Start out with the cheaper ammo if you need to watch cost and work your way up. I think the sierra guy was trying to sell you the deer can't tell the difference between a flat base or a boattail.