agree weight is always a factor. but 1 lb vs 3? From the pilots i know that isnt really the type of weight they are concerned about. esp if it comes to an item which may or may not need to be used to survive.
Same with behind the seat of a pickup truck.... not really necessary to have a "pack rifle".
I just assumed the Pack part referred to back packing but I guess it's smaller to pack in the back of your truck, plane or train as well though....