I don't understand--the ONLY response is "refer to a manual."
There should be no guessing or assuming.
My own method is to check several manuals and start at the LOWEST start load.
For 115gn FMJ bullets and Bullseye, start loads range from 3.5-4.5gn and MAX loads range from 4.0-5.1gn. I would certainly NOT start at 4.0gn or higher.
For 124gn FMJ bullets and Bullseye, start load range from 3.2-4.2gn and MAX loads range from 4.3-4.9gn.
To me, this indicates that the mix of components can have a major effect on pressure and you should NEVER assume anything, particularly that one manual has "better" data. It also shows that the 124gn bullets "typically" uses about 0.3gn less powder.
So, 4.1gn Bullseye with 124gn FMJ is just below the lowest MAX load and just below the highest START load.
I wouldn't risk it and I would use the start load, where most of my manuals used a 3.3-3.5gn start load.