"To initiate an adquate pressure to get the IMR4831 to burn fully, I seated the bullets into the rifling firmly. With this technique, the rifle shoots great, and the bore stays suprisingly clean and free of powder residue"
That is another good point, if the rifle will let you do it, bolt actions and falling blocks can certainly be tuned this way, maybe levers also. My 32-40 and 32-30 ran bullets fully breech seated in falling blocks.
And tuning with slower powders is a really good tip, it can make a big difference, as long as the alloy is good to go, to start with.
