Rainbow Six 1 and 2. Pre-Vegas.
Was a very good tactical simulation, all the weapons felt right. .45's had more stopping power than 9mm, the various rifles all did the right things.
They had a few shotguns in the various games, but the ones I remember were the Benelli M1 which I have actually used, and I used to own an M3. The game version seemed to behave correctly to me, as far as range and accuracy. Of course I never shot any tangos with mine, but I think I can still speak to how it should handle.
One of the things video games always do comically, is reloading tube magazines. either it is completely abstracted to a generic reloading action / sound effect, or it is absurdly fast. The first two R6 games did a fair job at getting it right.
Let me tell you something, doing tactical reloads with a 12 gauge is some fiddly shit. Watch some 3-gun matches on youtube to get an idea about exactly what goes on. People use all kinds of funny contrivances, from belt pouches to vest rigs to side-saddles. The higher end have these two-cartridge-per-slot side saddle setups where you pull two at a time and it doubles the speed of your reloading. There are lots of decisions you can make about when to select a slug or a different type of shot. You might be transferring cartridges between your vest and the side saddle so that you can get at them faster when you need them...
Capturing that in a videogame would be slightly less difficult than doing it in real life, but it is still something that the vast majority of game players dont want to fuck with. It is worth setting for a little abstraction in these things.