Had a bit of a play last weekend .
I loaded up some tes tloads starting at 27 grains of 4198 behind some 40 vmax and increased them at .2 grain increments.
Then shot them over a magneto speed as well as a Chrono.
I got to 28 grains with easy extraction but cratered primers. Velocity was 4240 FPS accuracy was .2 out of a Sako 85 with a factory barrel
Oh yes thank Camel