It sounds very, very appealing to me. I've been wild camping up in Scotland a few times, love it, except for the Midgies.
Consider getting a cheaper , more compact rifle, Ultra maybe. BUT , it sounds a bit iffy to take one up Scotland. If it where me and you where wanting to get the odd rabbit for the pot, maybe a few snares if your out in the back of beyond.
Good luck and enjoy your trip, sounds like a great adventure.