GRT and Vihtavuori N568?

[Silver_Is_Money]

I've often heard it said that N568 requires somewhat heavier charge weights than for N570, but GRT always tells me the opposite. Is there a means to correct the N568 parameters within GRT?

 

[Seabeeken]

There sure is. I would load a few rounds and shoot across a chrono. Take the speed data and input into the GRT OBT tool and there is a button to correct the powder model to YOUR rifle and cartridge. I do it for every rifle I have.