A few things that would nerf guns by making them more realistic rather than less:
Add/Bring back* increased recoil from being hit, if something smacks you when you’re trying to aim it tends to interfere.
Make reload times realistic. Currently the move or two taken to reload corresponds to a “tactical reload”, merely swapping out an empty magazine for a full one. Reloading a magazine can easily take upward of a minute, even for a skilled individual. This makes it basically impossible in a combat situation, and means you have to either fully disengage from enemies after running out of loaded ammo, or carry a bunch of magazines/guns that are pre-loaded, or switch to melee.
Impose some significant time to aim properly, especially for someone of low to moderate skill, they can consistently hit targets at a decent range, but not at a high rate of fire. Especially at low skill levels, time between accurate shots is fairly high.
I have a WIP PR for this that I ran out of time to fully polish: https://github.com/CleverRaven/Cataclysm-DDA/pull/2194
Basically it adds an “aim” stat that you have to accumulate by taking wait actions while aiming at a target, and is reset when you switch targets, move, or do anything else but aim. It works, but it needs a better UI, for example hotkeys to “aim and fire” to different degrees of precision**, and feedback on your confidence level of the current shot. This means while you’re aiming, you’re burning time, and enemies are closing in. Also this nerfs kiting with a gun since moving resets your aim.
One particualr point is rarity, I think this is a bit of a non-starter. It’s wildly unrealistic to make guns and ammo rare enough that it’s really hard to find and use some gun or another***. Guns in particular are really problematic, because you have to make guns rare enough that you NEVER find one, because once you’ve found one, you have it and that’s done. Ammo is a bit better, but it’s still quite unreasonable to make it rare enough to seriously impede usability.
Regardless, if you loot a decent chunk of a town OR a gun store, I’d expect you to be able to find a decent civilian weapon, and if you run across military content (dead soldiers, military base, etc) I’d expect you to come out of it with a couple of high-grade military weapons. A better approach for the military weapons at least is to restrict them to just military encounters, and spawn a lot of dangerous stuff around them to make the risk match the reward.
Side issue, craftable guns are kind of pointless for precisely the reason that in reality it would be FAR easier to loot a gun than to make one. I’m not willing to warp reality by making gun crafting easy and/or making manufactured guns rare enough that gun crafting is worthwhile. This limits gun crafting to gunmods, which is a fairly reasonable thing to do.
- I don’t recall this being removed, but there have been a LOT of changes, so I could have missed it somehow.
** Think “snap shot” vs “aimed shot” etc from x-com.
*** Frequency of military guns could use a nerf though, additionally some of the really good hunting rifles are likely more common than they should be.