Shot package hands down is better. Rangefinder increases the range at which your projectiles do max damage by a certain percentage, but due to how shotguns work, the pellets spread out further due to the increased range, meaning there is less chance that the number of pellets you need to be on target to get a 1 shot kill actually hit your target. Shot package is like a shotgun choke in that it concentrates the pattern of your pellets into a tighter grouping at any given range than you would get from the very same shotgun without shot package. Even though you do not get a range extension like range finder, what shot package does guarantee is that more of your pellets will actually land on your target, increasing the likelihood that you will inflict maximum damage and/or get a 1 shot kill. This is absolutely devastating when you combine shot package with high-impact shotguns.