ai.npc_valid_aim_cone	0.8
ai.npc_valid_mounted_aim_cone	0.92​

This is probably a better explanation on aimcone than I was going to post.

Aimcone is just what you call spread in other games. If you shoot you have an aimcone and somewhere in that aimcone the bullet lands, the bullets prioritize the middle though.

In Rust all the weapons pretty much all work in the same way, the first bullet you shoot is the most accurate (rifles have 0° - 0.25° aimcone the rest has somewhere between 0.5° and 2°) and the longer you spray the higher the aimcone.

Before the overhaul each weapon had a higher recoil and the aimcone stayed the same. If you trained enough you were able to control the recoil (on some weapons the recoil jumped left and right, not in a specific order but RNG) and hit many shots while spraying. Now you don't really need to practice the recoil of guns and RNG is a bigger part since you can't control it unless you stop shooting.