Hello everyone,

First post, yay !

Little background here, because I'm not sure you have that kind of question so often
I'm a French dev for a video game, I'm currently doing an overhaull on the firearm, so yup, as a French, I'm quite lost in the gunslinger universe...

Basically, our game is in 3D Isometric, and have currently only 2 guns (a "pistol" and a "shotgun"), I want to add new rifles, those rifles have to be realistic, and if possible quite common in Kentucky (it's where the game take place), and have to be powerfull enough to pierce a skull (zombies skull, don't worry , so I think it need to be able to kill a deer at least...)

So first I wanted something like a Ruber 10/22, but it look like not so deadly at long range.
So I thought, maybe a Remington 700 .223 and another .308, looks like really cool hunting/varmint rifles ! (I won't use these name in the game because of copyright, but just for the stat of the weapon like noise, average damage, precision, hit range, etc. All those stats are also based on the player "aiming" skill, so in my opinion a shotgun based on the Remington 870 pump action will be easy for a begginer, then the 9mm glock, then varmint rifle and finally the hunting rifle)

But now, I'm on the weapon upgrade, like scope, barrel, recoil pad and stuff, but I don't know what a barrel does for example.. So if anyone could give me some advice about it, what you use for a better hunt (because you'll find those guns in house while looting, like if they were used for hunting), any pros/cons on them ? (like you can't aim at close range with a scope, and a himp shot isn't really accurate), even part to lower the weight, etc..

Slighht edit : Also could you tell me if those upgrades can be put on the rifle easily by the average joe ? Does it need tools like a screwdriver, etc.. ?

Thanks a lot guys