243 and 6 creed would likely be happier with 4350 powders unless you are using pretty light bullets. If you have to use one in these I think varget would do better.which is more preferred, H4895 vs Varget
I load:
223
243
6mmCrd
308
I would say 223 likes h4895 more than varget and 308 likes varget more than h4895 but its comparing gold to platinum in each. Cant really go wrong.
If you had to go with one for all calibers listed I'd go with varget.