I would have to disagree with the T/C fella you spoke to about shooting conicals out of a 1:28 twist. Many of the folks on this board, including me, have had very good results shooting heavy conicals out of 1:28 T/C rifles. I use a 410 gr. Hornady Great Plains with excellent results. A number of folks rave about the 460 Gr. No Excuses concicals. And the Powerbelts are technically a conical - they shoot great in quite a few fast twist guns. Maybe the 1:48 twist is optimum, but the 1:28 can produce great groups with the heavy slugs.