This mod's goal is to tweak weapon attributes to make them behave more like their real world counterparts, while keeping them balanced in the context of the game. Important changes include extended effective range for most weapons and tweaked accuracy, damage, rate of fire and magazine capacity for some others. The net result of all this is the weapons are more logical in terms of specs and capabilities, are more satisfying to use and -- under the right circumstances – are significantly more effective, both in the player's hands and in the hands of their opponents.
Summary of changes

* The effective range of almost all of the weapons has been extended. Previously the effective range of most weapons (but most noticeably the assault rifles) dropped off too soon and too suddenly. This would, all too often, leave the player able to clearly see a target but not hit it. This has been rectified. While before a bullet fired from an assault rifle could hardly cover the length of a city block before disappearing into thin air, assault rifles can now be used to target enemies out to a few hundred meters away.
* Magazine capacities of certain weapons have been changed to reflect their magazines' actual dimensions (for example, the Micro SMG's magazine is too small to hold 50 rounds, it is actually a 32 round magazine. Likewise with the Pump Shotgun, the tube magazine of which is too small to hold 8 shells, it actually fits only 4.) and changes in caliber (the Pistol, despite appearing to be a 9mm Glock 17 at first glance, is actually a Glock 22 in .40 S&W, the stats have been updated to reflect this.).
* The damage of certain weapons has been increased, while the physics force of most weapons has been decreased (the only exceptions being the shotguns, their force has been increased slightly). Appropriately, given their calibers, the Assault Rifle (AK-47) is now more powerful than the Carbine Rifle (M4A1), though it is slightly less accurate.
* The shotguns have been changed significantly. Both the Pump Shotgun (the short one) and the Combat Shotgun now have slightly smaller capacities (4 and 8 respectively), but they are significantly more powerful, moderately more accurate and have extended range, particularly so in the Combat Shotgun's case
* The maximum ammo capacities of most weapons has been reduced to 10 magazines' worth or less (For example, the AK-47's maximum ammo capacity is 300). True, it's still unrealistic, but not as excessive as before.
* The accuracy of some weapons has been increased slightly, while others' accuracy has been reduced slightly. This is all very subtle, the biggest changes in this regard were made to the shotguns, and even those were only slight, to avoid creating issues with AI targeting.
* The rates of fire of some weapons has been adjusted. The Desert Eagle's rate of fire has been reduced to simulate Niko absorbing and compensating for the weapon's heavy recoil, while the rates of fire of the Micro SMG, SMG, AK-47 and M4A1 have been increased, with the M4A1 having the highest rate of fire. Previously, a bug caused the SMG's blindfire rate of fire to be noticeably slower than its normal rate of fire, this has been compensated for, so now the weapon fires at exactly (or almost exactly) the same speed however it's used.