I think my favorite piece of hunting gear, based on how much i use it, would be my Swarovski Optic 8X42 binoculars. I bought them over twenty years ago and they are probably the best investment in hunting gear I ever made.
I'd have to pick my dog. Dog, you say? I know she isn't "gear" per say but I can replace gear by buying it from the store. I'll have a hard time finding a dog that will provide the memories she has. She's ready to go the minute I pick up the keys in the morning, out the door. She'll go in the nastiest cover to retrieve doves and ducks. She has found more than one deer in some nasty thickets with little blood. Minds better than most children. I'd miss her more than any piece of gear I have.
What does "gauge" mean anyway? As used here gauge means the number of round lead balls the same diameter as the inside of the barrel (aka the bore) that it would take to weigh one pound. It takes 12 lead balls the same diameter as a 12 gauge barrel to weigh a pound. The smaller 20 gauge would require 20 balls of that barrel diameter. The larger bore 12 gauge would require 12 lead balls of the bore diameter to weigh one pound.
In general the number of pellets in a shotgun shell...