I stumbled across this earlier tonight, every time I use this combo, when I fire my first shot the sound goes dead - for everyone in server.
I wasn't sure that it was me, so joined several servers to test. Same effect every time. Doesn't make a difference what gamemode or player count.
I didn't want to report it in the forums and was looking for a direct link to report a (pretty serious) bug, but after contacting EA was advised to do so.. :S
update, it actually dosen't turn off the sound for everyone, only those within earshot. On a small map this means everyone normally anyway.
