We are not hunting or self-defence so RNFP will work for cowboys ,Silhouettes, punching holes in paper or tin cans. The few that might be hunting with a 45 colt will need a RNFP to cycle in a rifle and the flat is almost the same with a higher ballistic coeffenit. Right side please.
Also the RNFP has a better lead into the crimp groove for a firm crimp without lead shaving, so you can seat and crimp in one operation. The SWC with a tighter crimp is best to crimp at a separate step.