The 200gr may only hit a little lower than 250gr and may be an issue with some guns- nothing that powder charge modulation (if using smokeless) and Kentucky windage can't help.
If you are going to be using holy black, your only choices are to fill it up so there is about 1/16" compression under the bullet, or add a wad under the bullet to take up a bit of room, and create a better seal and thus shoot more cleanly. Forget the wads at first to keep it simple.