When I started loading for my 444, the closer I got to max loading the better the accuracy. I'm using IMR4198 and that will also work in a 45-70 as well. It's probably the most versatile powder out there. I'm using the Hornady 265gr bullet and getting more than the 2300'ps but I was using older data, before the lawyers got involved, and will probably reduced the load when I start reloading for it again. With the 444 I haven't found much, if any, difference in primers effecting how the gun shoots. Mine shoots the current load right at 3/4" group at 100 yds which exceeds my expectations.