I have a 4" GP100 in a lock box bolted into my floorboards and a former PD 18" 870 Wingmaster stashed under the back bench seat. I need to fabricate a locking bracket for that one. In fact it's been on my to-do list for about a year now. Might need to go ahead and take care of that...........
As to why I selected these two:
GP100:
1) Versatility: Anything from mild to wild in terms of ammo. Anything from 2 legged predators to 4 legged game and/or predators. Biggest thing I'd have to worry about in my usual haunts is black bear.
2) Durability: It's stainless, it's a Ruger. I don't worry about it being stored long-term in my truck. It is in a padded recess in the lock box along with speedloaders for .357 and speedstrips for .38. It's loaded with .38's. I do take it out about once a month (every other range trip or so) and shoot it and wipe it down with CLP.
870:
1) Versatility: Anything from mild to wild in terms of ammo. I've got a box of birdshot in a belt carry pouch under the seat with it as well as a shell belt full of 00 buck. There are also slugs in the sidesaddle. I figure if I'm stuck somewhere remote I can eat, regardless of what game presents itself.
2) Durability: It's an 870 and it's already ridden shotgun in a few patrol cars over the years. I ain't worried about the finish.....I do however keep it in a silicone impregnated gun sock and I take it out once every other range trip or so and run a few shells through it and wipe it down. I have installed a tritium front bead on it as well. When it gets to the point where the bluing is so far gone that it's just too ugly to look at I may consider duracoating it. For the time being though it's still purty enough.......