Phil
like others have said, I think you could have used a 223, 204 20 tactical or even a 20 vartarg seater. but it's always nice to have a dedicated die for the caliber you are loading for. however, I don't think it will make it will make your kill ratio go up. there's only one way to know for sure. load several hundred with the new die and several hundred with the old die and I will shoot them for you and post the results. it's the scientific approach.