Slow burning powders in 6mm

I've got a little experience with Win 785 in the 243. You can't use reduced loads with this, and only the heavier bullets, say 90-95 grains and up. Obsolete powder, designed specifically for the 243.

I have used Varget for years in .243 and other powders in that burn range and have given me the best accuracy...one rule of thumb is that the longer your barrel the slower powder you can use....You want to make sure your powder is burnt up before the end of the barrel but the opposite is also true...You do not want your powder burned up right away as then the friction in the barrel can start slowing your bullet before it even leaves the barrel....so some experimenting with your particular rifle and barrel on paper is the only way to really see what is going to work for you.....