We have been experiencing some muzzle flash bugs ever since we've ported Orion from the EP1 SDK to the Orange Box SDK.
They worked perfectly when we were building on top of the HL2 / Episode 1 engine. However, after our port a few months ago to the Orange Box engine they DO NOT appear.
We had one developer in the past that had made one of our weapons (Human LMG) work with muzzle flashes, but it was mostly out of luck.
Here is an example of a .qc compile script with its compiled corresponding model. This weapon DOES NOT display muzzle flashes in game.
If anyone has any knowledge regarding this I would really appreciate it so I can fix it.
If anyone is able to help us re-compile and get all of our muzzles working, that would be even more awesome!