have been using the DEAD CENTER BULLET .260 gr. for a while ,very accurate in the summer ,but as soon as the temperature went cold they were no more good ..i use T7 powder [100 gr. ] and was very disappointed. .i have a ROSSI 50 cal ...so i switched over toT/C shockwave .250 gr. and they are tighter in the barrel and they are very accurate at 100 yards ..the HORNADY SST [red nylon tip] seem to be the same as the SHOCKWAVE .