A standard bench vise -- for a lot of gun work -- will just drive you nuts because you won't be able to orient the gun the way you want to a lot of the time. Trust me -- I used one for over 40 years, and cursed its lack of usability a lot in the case of guns.
I have two vises that I use for gun work. The first is a
low-end Tipton "Gun vise" that I most frequently use for cleaning and minor disassembly/assembly stuff. It's okay, but what's really irritating about it is that the way it clamps the butt stock sucks for many guns (especially black powder) and you just can't clamp it so it's vertical and solid -- at least without some bizarre shimming. But for simple stuff, it's okay. If you do buy one of these, you should consider one of the slightly more expensive ones -- and think about what you mostly want to use it for and how usable it would be for that.
About two years ago I finally bought one of these
Multi-Purpose vises. I really needed something like this for decades, but kept putting it off. VERY versatile (rotates in two different planes), and even more versatile if you get a set of different jaws or jaw pads, or make some for it. For me, I think it's better than a pattern-maker's vise or other similar speciality vises. With aluminum, plastic, wood, and rubber jaw (or jaw pad) sets, it covers a lot of ground. And you can orient a gun (or a part) in it pretty much however you want. There's a wide range of cost and quality here. I went relatively low end because ... er ... for most practical purposes (short of precision machining) a vise is a vise is a vise. I thought the Irwin looked better than the Harbor Freight. That's pretty much the depth of my thought on the subject. But if you have $1,000 you want to spend on a vise, by all means, do that. You need something solid to mount it on -- and in such a way that you can take advantage of each of its rotational capabilities.
