SIG SG552 Assault Rifle:
Accuracy adjusted to be less accurate at all times, while spread is barely affected by shooting. In general should have a tighter spread than before when un-scoped full-autoing but be much less effective during semi-auto fire until you scope in.
Recoil reduced significantly.
Scoped mode remains at the same accuracy.
DPS increased to 550 from 500 (325.6 from 296 DPS while Scoped.)

All Sniper Rifle class weapons:
Unscoped accuracy reduced significantly.
Scoped accuracy remains unchanged.

Pipebomb:
Fuse time increased to 8 seconds from 6

Grenade Launcher:
Stagger radius increased significantly

Grenade Launcher buffed:
Explosion radius increased.
Damage increased to 2500 and bonus vs Tanks removed (666.666666 dps at 0.2666666 rounds a second)
Friendly fire to team-mates removed.
Self friendly fire damage capped at 250 damage (i.e don't shoot your feet on Expert...)
Recoil massively increased.

Incendiary ammo burn time extended to 10 seconds from 4.

Laser sight spread reduction bonus reduced to 30% from 60%.

Shotgun ammo counts adjusted very slightly: 98 for Tactical and 99 for SPAS12.

Chrome Shotgun reserve ammo returned to the same as the new Tactical.

Shotgun Damage multiplier for being at very close range as been decreased and requires you to be closer to activate it. This makes 'Cr0wning' witches much more difficult and prevents Shotguns from turning tanks into swiss-cheese in seconds. Cr0wning is now a real expert's skill and not for normal use.

Pistol Accuracy reduced and recoil increased somewhat.

Chainsaw adjusted to compensate for it's massivly increased usability: DPS reduced to 700 from 1000 (still the highest DPS weapon in the game,) Attack 'Cone' reduced to 20 degrees from 30, hidden damage resistance to claw attacks (common and special) removed and now attracts zombies from much further away.

Applying bug-fixes kindly provided by Mrz.FranG00bYGAIBEN1337H4x0r$MLG.
Should fix any issues being had with other game-modes apart from Co-Op while using this mod.

Adjustments to shotguns: Damage per shot increased for both auto-shotguns while more spread while moving and standing compensates for this. Tactical Auto-Shotgun now acheives this new damage with 6 pellets rather than 12 making it more lethal at longer ranges, albeit less reliable.

Sniper rifle damages and fire rates adjusted: DPS between the Hunting and Millitary rifles standardised (That is the Hunting rifle was buffed to the Millitary's level) and Hunting rifle fires slightly slower allowing for more damage per shot

Silenced SMG damage adjusted to lower it's DPS somewhat while maintaining it's crowd-clearing capabilities.

AWP Clip Size and Reserve Ammo reduced to 3 and 21 respectivly to further limit the use of this extremely effective weapon. It was pretty god-like before, and still is but you need to be more sparing with it now. Shooting Boomers and Spitters with it is no longer such a great idea: Gotta save those bullets.

Chainsaw Fuel amount reduced (will actually run out from extended use, but in a much more believable timeframe than vanilla which also improves it's usability. Should still be able to keep one running from the start of a campaign to the end of one with careful use)

Ranges and ballistic curves adjusted. Generally speaking most bullets fly further. However they also better suit the role of the weapon (i.e accurate weapons fire further and vice versa)

Whoops...
Forgot two other small changes:
Hunting Rifle returned to Tier 1 to fill the missing Tier 1 sniper role
Pump Shotgun damage buffed somewhat.
Chainsaw now has enough fuel for 1 hour of extended use (as per reality)

Usability improvements for the AWP and Silenced SMG
Buff to damage for Chrome Shotgun
L4D1 version launched

The final round of complete balance changes. Everything should be in a pretty good place now.
I will mark this mod as complete now, but will still return for minor updates, specific balance changes and bug fixes. Enjoy~

Entering the last round of balance changes.
Almost all weapons adjusted relative to each other.
See new descriptions for details.

Minor Rebalance changes.
Weapons now start with no ammo in their clip and must be reloaded.
Also did some work on the Counter Strike weapons: See the discussion page for details