This mod from Chuppachup tweak weapon stats and includes the Normal Accuracy mod. See File Details for specifics.
I must stress that the basic original GSC config settings have not been altered very much at all - they are pretty good as they are - these are minor tweaks and in large part are based on weapon characteristics described in the STALKER Survival Guide. Some of this involves sort of lip service to realistic characteristics and traits but in no way is any of it seriously aimed at being "True to Life" - it's all to do with producing a certain "feel" for different weapons within the GAMEPLAY experience. Main changes:
* Physics effect of hits is reduced across the board - there may be a bit of throwback and you should see a bit of movement of corpses if you hit them - but not the wild flinging of the standard setting.
* All pistols have relatively short range - all between 50 and 70 meters according to type (this actually involved reducing the range of only a few types).
* MP5 is made to virtually be an auto version of the PMM (tho it's range is greater) and it's recoil makes accurate repeat fire fairly difficult - best used in close quarters (hey, that's what it was designed for).
* IL86 is made less reliable and with difficult recoil - tho it's basic accuracy is very high.
* 5.45 rifle ammo has better penetration than 5.56
* 5.56 has bit better hit power than 5.45 as well as better basic accuracy.
* Spas 12 is made less reliable.
* Shotgun ammo is tweaked - Slugs and Darts are devastating - particularly Darts which are more accurate and have much better penetration than slugs (downside is rareness of ammo and slow reload) - recoil is made a bit worse to make up for better effectiveness of the ammo. Nothing beats a long barrelled shotgun and Darts for bringing down Specznaz, but make sure you have cover for reloading.... Buckshot is tweaked as well just for better "feel" - is devastating at short range against weaker mutants and poorly armoured NPC's but pretty much bounces off armoured enemies.
* Wallmarks made larger for Slugs and Darts and .45 calibre hits.
The changes I made to 5.45 and 5.56 ammo is based on the fact that the 5.45 round is a physically longer bullet than the 5.56.... - this predictably enough results in a characteristic where the 5.45 penetrates better versus the 5.56 round tending to spread and topple quickly (a Youtube video clearly demonstrates this) - hence I've made appropriate changes to the ammo configs. My aim is to make the character of 5.56 weapons and 5.45 weapons more distinctly different. In a broad sense this makes 5.45 ammo better for closer range high volume firefights and 5.56 more useful for aimed hits on vital parts (ie. headshots) - with 5.45 weapons becoming more effective as range decreases and 5.56 weapons becoming more difficult to be effective with as range decreases (the difference being less obvious with weakly armoured opponents vs much more significant against heavier armoured opponents). The aim is to make the way you have to use each type of rifle ingame very different. The MP5 I have always had a problem with from the point of view that - as it is configured in the game - it really almost makes AK74 family obsolete - so my preferred option is to make it an alternative to pistols AND shotgun with buckshot - ie. if you prefer to aim at the head and take measured shots then a pistol is still the way to go - but alternatively you can use the MP5 in bursts at the centre of mass. I have stopped short of putting the MP5 into the pistol slot as that's one of the balance factors that keeps pistols "useful" and otherwise might well make all pistols obsolete once the player has the MP5. Really I guess my MP5 becomes an alternative in certain situations for both shotgun with buckshot or for pistol - ie. shotgun / buckshot is very effective against weaker mutants but pistol isn't as effective - and pistol can be very effective against even moderately armoured NPC's within it's range, but shotgun / buckshot won't be - yet my MP5 will be as effective as either of those in either situation (as long as you have sufficient ammo).
Anyone can of course use any of the actual settings and/or ideas/concepts in these configs - no permissions or credits required.
Looking at the configs using notepad is worth doing as many of the values are self explainatory. One specific people might like to change is putting the MP5 into the pistol slot - to do this, open MP5.ltx and look for the lines:
slot = 2 ; // secondary
animation_slot = 2 ; type of the animation that will be used
Change the 2's to 1's and you'll have MP5 in the pistol slot.