I use Varget very successfully in my .223, .243, and .308.
I've shot prairie dogs with the .243 at 700 yards and have done the NRA highpower with the .223 at 200, 300, and 600 yards, and Palma match at 800, 900, 1000 yards with the .308.
It is a very good powder and it is NOT temperature sensitive.
I'd go to the Hogdens web site and ask them for your bullet weight.