Infinity Ward, the makers of Call of Duty Modern Warfare 3 released an update to the game yesterday.
Hot Fix Updates (Releasing Today 12/12/11):
Fire rate normalization for Assault Rifles with undermounts
FMG9 Re-balancing (Nerf)
Akimbo FMG9 Re-balancing (Nerf)
Type95 Re-balancing (Nerf) – Reduce hipspread.
Fix for ACR with Red Dot / Shotgun
Fix Type 95 bug related to dropping it.
Fix map exploits on Dome