thicker/thinner? Rim 44-.514, 30/30-.506. Thick-44 mg, 60 , 30/30 .063, then the difference, the diameter of the 44 Mag case in front of the rim is .457, the 30/30 case diameter is .422. that leaves .035 thousands smaller diameter for the 30/30 than the 44 Mag. what difference will it make? I do not know, but the case may not center and when lowering the ram the rim could be less rim contact with the shell holder.
The deck height should be the same, .125.