Using 200 grain lead bullet data with 190 grain lead bullets of the same diameter, composition and construction, you are probably going to be okay.

But note that it is not only bullet weight but composition and configuration that impact velocity and pressure. Two examples:

1. If the lead in your bullets is made from a different, harder alloy than the bullets used to devleop the test data, it will take a higher level of pressure to get the bullet to engage with the rifling.
2. If the bullet you are shooting has a hollow base then the propellant gasses will fill the hollow pushing its margins into contact with the rifling making it harder to move and thus requiring more pressure. If the bullets used to develop the load data had a flat base, they would not require as much pressure.

Begin with the starting load in your load data. Be alert to whether anything sounds or feels "off" when you shoot them and inspect the cases after firing for signs of pressure and then work up as indicated.