I have two main configs, both centering on the SCAR-H
Config A)
Primary = SCAR-H w/Thermal Sight and Grenade Launcher
Secondary = PP2000 w/Red Dot Sight
Semtex Grenades
Smoke
Perk 1 = Bling Pro
Perk 2 = Cold Blooded
Perk 3 = Scrambler Pro
Death Streak = Martyrdom (hardly ever get a kill with it)
Config B)
Primary = SCAR-H w/Thermal Sight and FMJ
Secondary = Stryker Shotgun
Frag Grenades
Smoke
Perk 1 = Bling Pro
Perk 2 = Cold Blooded
Perk 3 = Scrambler Pro
Death Streak = Martyrdom (hardly ever get a kill with it)
I also have a Sniper config along with an AUG and an RPD.
I only have one config with an anti-vehicle weapon. And, even though I've unlocked better weapons I'm sticking with the AT4 because you can fire it without locking on, which allows you to fire it at people, which comes in handy when your primary is empty.
All these setups are subject to change, of course. I tinker all the time.
One Perk I might go back to is "Hardline" which allows you to get the Kill Streak bonus with 1 less kill. That can come in real handy.
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"All religion, my friend, is simply evolved out of fraud, fear, greed, imagination, and poetry."
Edgar Allan Poe