[Chris Chávez]

I recommend learning how to jump around and snipe (quick snipe). It's much easier on SOCOM 3, and is extremely useful when an assualt rifle is coming at you. With the low accuracy (or skill, depending on who it is) of the guns/people, jumping around and sniping can help you live.

What I do:

Equip an M87ER or M82A1A
attach a Bipod and 12x OR High Scope
Get whichever pistol you want, with no attachments.
No grenades, extra ammo, claymores, etc. That way you'll be able to run and jump with ease and speed.

I usually go prone and snipe until I see a threat coming towards me fast, then jump around and try to snipe him. So far, I've probably gotten about 75% of the people who have rushed at me with assault rifles.

Another helpful tip - if you find yourself within feet of an enemy, and you have your sniper rifle out, open scoping is actually very effective in S3. I've killed 3 people, open scope, in a row in a few games.

These are more of recommendations for you to try than they are tips, but they've proven very useful to me. Knowing how to snipe while in a tight situation along with sniping while prone can allow you to be a valuable asset to your team.