I'd have the barrel turned back a touch and be done with it. Why treat the symptoms and not the cause?

Is it just me, or does seating so that the cartridge headspaces by jamming the bullet into the rifling sound like a really bad idea no matter what powder you use. Secondly, there aren't too many powders that will allow one to do this at all, let alone in a rifle with excessive headspace, and I doub't you'd find tested load data for this stunt. The result would probably be a gross overcharge compounded by the bullet being jammed into the rifling, which is a recipe for disaster, IMO.

Mike