Shot package is more useful. 1. Rangefinder increases the range, but at the range you will be able to deal damage, you won't be able to hit pellets. 2. Felwinter's lie has near max range without hammer forged, so with hammer forged, rangefinder is redundant. 3. Shot-package keeps pellets on target, meaning your 1-hit kill potential from longer(ish) ranges will be higher. With the slow RoF on this shotgun, it is VITAL that you kill on the first shot.