In the first installment, I covered assault rifles, submachine guns, and my personal favorite, shotguns.
A handgun will almost always take the role of a secondary weapon, but that doesn’t mean they can’t pack a punch. They do, however, have smaller clips, shorter range, and are usually semi-automatic. Some of them can be used in conjunction with the knife, making for some quick and deadly CQC kills that are faster than normal knife swings.
Handguns usually prove more useful in multiplayer, where the need for speed – both in movement and weapon switching – is much greater.
You won’t come across many sniper rifles in the single-player campaign, but that’s no excuse to be uninformed. Besides, you’ll see a good deal more in the Spec Ops missions. Sniper rifles provide fantastic long-range accuracy, something I’m sure everyone is aware of. The best tactic with these rifles is to pick off enemies before they’re close enough to qualify as a threat.
When you do come across sniper rifles in single player, be sure to grab them. Take out everyone you can in your current position, and then swap it for something else before heading out.
There are a few heavy weapons in Modern Warfare 2, such as the RPG, AT4, Javelin, and Stinger. While you probably won’t be using them against enemy infantry, they’re absolutely crucial for taking on hostile vehicles.
In most vehicle battles, there will be a heavy weapon nearby for use in that specific instance. You probably won’t be toting them around for very long.
Heavy machine guns are also scattered throughout the game and do wonders against large waves of enemy soldiers. They have massive clips and when fired in short bursts, can be as accurate as assault rifles. Never blast away at full auto, as the recoil makes proper aiming nearly impossible.
Article from Gamersyndrome.com