I have been testing IMR 4064 (56, 58 , 60 Grains) with the 150 gr. Nosler CT silvertips. Trying to get things as close as possible to the factory Winchester 150 silvertips.
Those factory silvertips had a much higher velocity than what I am getting though....
I'm going to keep cranking things up (As long as things look safe) until I get the velocity that my silvertips shoot dial reads then I will start playing with the BOSS to try and tune the groups in. (I will probably end up around 60.5 grains to achieve that 3275 ish)
The only thing that is for certain is that I have a lot to learn still with reloading rifle shells.
Thats the nice thing about the BOSS. You can really expand and shrink groups once you get the velocity you want. My A-bolt can be tuned to just about any bullet. Dont know why they got rid of it. Maybe because it will deafen you without earplugs...lol
https://load-data.nosler.com/load-data/300-winchester-short-magnum-wsm/