Agreed, Varget is not well suited to .260 and the140-ish bullet weight range. It's going to be usable (but not especially useful) in the 34-38gr charge range, and the load density will be very low. Varget was the choice back in the early 2000's, when the cartridge was still getting up to speed. I've been loading for it since 2001.
I have used the Sierra 140 and 142 SMK, and 140 A-max with 42-44gr of H-4350 in a 28" barrel. Up above 43gr, it's getting on the hot side. I'm trying the new 143 ELD-X with 43.5gr as a ballpark beginning load, and I suspect I'll be going lower rather than higher as I develop it further.
Because of its popularity with the .260 and 6.5CM (and others), H-4350 is getting scarcer.
With the really longer barrels, like my 28", H-4831(SC) can be another good choice, because the extra barrel length can allow the slower powder to achieve a better burn. I have looked for the H-4831 max with these 140's and been unable to find honestly excessive pressures within the .260's case capacity using conventional loading practices.
What I found was lower velocities with similar charge weights to H-4350, but also some pretty nice accuracy as well. At the time (mid-2000's) I was thinking I needed highest attainable velocities, but that has since proved both unnecessary and probably unwise.
If it seems appropriate, I will revisit H-4831 with the 143 ELD-X. I think that's a given, and I also think it will deliver better pressures, and maybe better bore life.
Greg
