The "standard" is to back off 10% from max load for the listed bullet when you change any other component, and then work back up. There is no standard or formula to figure for a lighter weight bullet, or differences in seating depth from a different type of bullet. There are just too many variables to deal with in reloading for that to happen.
When you change bullets, and especially when you change bullet weights, you need to find new data.
Sometimes, depeding on the cartridge, chamber, and powder being used, you can compensate for slight variations in bullet lengths by adjusting the seating depth. This is not always the case, however, and you need to know exactly what you're doing if you try it.
It's easier and safer to find data for the correct, or at least a very similar bullet.
A government that abrogates any of the Bill of Rights, with or without majoritarian approval, forever acts illegitimately, becomes tyrannical, and loses the moral right to govern-Jeffrey Snyder