WE did a lot of testing with ramshot TAC in 308 win about 8 years ago when the powders first became available in the uk. A fine ball powder it flowed extremely well through our harrell powder measures. Worked very well in bullets weights from 125 to 168 grains. We did find it slightly too quick in burning rate for any bullet heavier than 170 grains.
Accuracy was as good as anything we tested from alliant / hogdon/ vitavouhri. Good case prep and loading practices gave very consistent extreme spreads and standard deviations over the chronograph. I would not hesitate to use it again, but continuity of supply would be my only concern . If you need any data please call me on he workshop number and I will dig out my data files and avail you with the relevant load data. Yours respectfully Mike Norris Brock and Norris Custom Rifles