I have a standard taper Savage .243 with a 1:9.25 twist. I don't use factory ammo, but it does very well with anything from a 55 grain to a 100 grain bullet. I agree with npd, if you're looking for a single load for woodchucks to whitetails, go with an 85 or 87 grain bullet, but I don't think you need a premium bullet to do the job.