While H-380 is a great powder, it' s intended for the medium size cases and lighter bullets(243 win, 22-250 rem). It will work as does ok with the light 100 gr bullets in the 270 Win but it' s burn rate is a bit too fast for decent velocities with 130,140,150 grian pills in my opinion.
You are right in saying that it' s a fine spherical powder, it meters great through powder measures! IMHO I would use the old standby for the 270 Win which is H-4831, it' s performance is outstanding in this cartridge with the previous mentioned bullet weights. The velocities are good with decent pressures.



Dont get me wrong, like I said H380 is also a good powder, I have burned many pounds of it in the 22 centerfires but you wont be disappointed with a slightly slower burning powder such as H-4831.......AA