Gunlag is currently working but overall, the weapon system is still a bit of a mess and incomplete or broken in several areas.
There is a lot of potential here but it's got a ways to go yet.
I am currently compiling a new issues list for the weapon system and putting together a sort of guide to help people understand what all the settings are and how to use them in GG.
Gigabyte P67A-UD4-B3, Intel Core i7 2600K, 16GB Corsair DDR3, EVGA GTX 970 SC, Win7 Pro 64-bit SP1, Primary monitor @ 1920x1080, secondary monitor @ 1024x1280