Your rifle is not strong enough to contain the most powerful loads I use in my Ruger #1. But if you must, use the RCBS 405gr. bullet and keep adding RE7 or IMR 4198 powder until either you can't stand the recoil anymore or the action pops open when you fire it. Then back off a touch.
Seriously, what you are asking sort of doesn't make sense. Loaded to 1200 fps with black powder, that bullet will shoot clear through pretty much anything on this continent and doesn't hurt you or your rifle. If you want a flatter trajectory, use a different cartridge. If you are just doing it to see what happens, that is another matter and go ahead and have fun. After you see what she'll do, then back off to a reasonable speed and enjoy shooting your rifle for what it is designed for.
Oh, a case full (to the base of the seated bullet) of IMR 3031, 4064, or 4895 will not overpressure your rifle and will likely give you all the excitement you care to stand. About 1800 fps or so.