When firing a gun and using 5.1 (not sure about 7.1) surround sound, the only channel that the sound comes out of is the center channel (aside from some minuscule sound from some rear speakers). This is the same in first person as it is in third. The shots should be able to be heard from all speakers in some form or another, or move around as the player holds alt and pans around in both first person and third person.

The same goes for the engine sound of player driven/piloted vehicles and aircraft - center channel only.

It would also be nice if it gave the subwoofer something to do, but that should be included along with the other speakers.
The sound simply sounds lacking when you're shooting a gun right in front of your face and then only hearing it from one channel out of a possible several