Inside the nipples of the Gnome I use to prop up my Kitchen Table.
My advice is this: There are 3 choices when engaging in CQB. (Close Quarters Battle)
Scar Black + Red Dot + Ammo+10 Clip, not the +15, the + 10
M416 + Red Dot + Ammo+10 Clip, not the +15, the + 10
G36E + Recoil Suppressing Silencer + Ammo+10 Clip, not the +15, the + 10
The Scar Black has a little spread and isn't fully accurate, but you'll be thankful you got it in CQB. This is also good for light sniping, don't count on hitting more than 60% of the time though unless you are the Sniping Warmonger.
The M416 is the newest monster of the Combat Arms armory. With a great sight, it makes for excellent sniping ability. Next to no recoil or spread is a high-end plus. I personally would rather have this in my second slot than a LAW.
The G36E is the staple gun of all Combat Arms. Despite some spread, the recoil can be overlooked by it's nasty stopping power. A built in scope makes this a Sniper's best friend when his rifle is out of ammo or he finds himself in a CQB situation. This gun has saved my life more times than I can count. I have never gone into a battle without hitting a minimum of 20 kills, even in mid-combat.
As for you though, you'll just have to try these settings and see for yourself which suits your style best. My advice is to gather enough GP to test these out all in 1 day with the settings displayed here. At the end of the day, you'll find yourself holding the gun you feel best with.