A friend of mine has had two Rugers, one a Redhawk and the other a Super Redhawk that needed at a minimum .433" bullets for the same problem. For the Super Redhawk he has now he went to NOE to get a .434" mold and to I think it was Buffalo Arms to get a .433" sizer die to fix the problems like you described.Unless you use bullets that are over size ( I have a .44 that requires .4325" bullets to not lead the bore) the Lee crimp die is the way to go. Adjust your die deeper a little at a time until the crimp is to your liking. I've used them for years on all my handgun cast bullet cartridges (except that one pesky .44) ranging from .38/.357, .45 ACP, .44 Magnum and .45 Colt with great success. Added benefit is that the die "irons" the cartridge as it is withdrawn so it easily chambers.
A friend of mine has had two Rugers, one a Redhawk and the other a Super Redhawk that needed at a minimum .433" bullets for the same problem. For the Super Redhawk he has now he went to NOE to get a .434" mold and to I think it was Buffalo Arms to get a .433" sizer die to fix the problems like you described.