Reverted to default Valve sounds for the reloading and handling.

Belated Last Stand patch update:
- Slightly re-adjusted shaders to give the item a more metallic look
- Changed shooting sound
- HUD icon now included without needing secondary add-on

- Fixed more smoothing errors
- Reduced overbrightening in shaders
- Changed particle setup

- Fixed numerous smoothing errors I initially didn't notice
- Fixed the odd shell eject angle
- Tweaked the shaders/VMTs