Well, did you happen to notice my target above these post? They were shot with basically the same gun as yours, same brand, barrel length and caliber...and the bullets were sized to .432 diameter.
So, please consider the .432 diameter size bullets as your finished bullet size. But I won't insist on you doing it, but it might help.
Another thing to consider is seating an over sized bullet in most standard reloading dies and getting a proper crimp. Too big a bullet diameter may be a problem.
If our gun barrels are .429 and we are using .432 bullets, that's big a step down in resizing the bullet when it hits the forcing cone and enters that smaller diameter rifling. It won't hurt anything because I've been doing it since last year.
I've even been doing it with Lyman #429244 GC bullets that are 265 grain in weight. Though these loads are not hot loads. If you want hot loads, one should be using a .44 magnum.
See target using 265 grain bullets that are sized to .432 diameter...shot at 20 yards.
Jim