You asked and I do things a lot less technical. I only load to half a grain.....just what I do. Based on your info I would do nothing other than try 37.6 if no pressure signs and the accuracy is where you want it.....stuff em and shoot em. If pressure or less accuracy and your getting the velocity you want I would go back to 37.1 and if you want more accuracy ( I would be done) then adjust your seating depth 10K closer if it gets better another 10K. If it got worse the first 10K back it off to 40K off and see what happens. Based on those last groups adjust 5K and see what happens. As I said if it didnt get better, you want to shoot that bullet, powder, primer combination I would load and shoot 30K off and 37.1