I am the god of hellfire, and I bring you...! (BF3 Soldier build)

11/6/12 Edit: Slightly revised build, in regards to buffing damage from Carnage. Also did some math. Results are absolutely sublime - the damage you deal against armour is insane.

Fire! I'll take you to burn...doo doo doo...

Remember when the patch came out all those weeks ago? There was something in there about Carnage priming Fire Explosions. And my immediate thought was "wow that'll be pretty cool for BF3 soldier, seeing as he would actually have a way of using Carnage as a primer." But until recently I didn't bother trying anything out. Now, I've spent some time experimenting, and I've found something I really like. No longer will the BF3 soldier be just another AR soldier, variety is the name of the game and we're going to make full use of his powers to turn him into a really unique class.

Build

Yes, I am skipping Adrenaline Rush. It's not the focus of this build. The focus is instead, FIRE EXPLOSIONS EVERYWHERE MWAHAHAHAHAHA!!!! Besides, the Reegar is freakishly strong already and really doesn't need the extra damage.

The Battlefield 3 soldier is unique in that he's the only class with Carnage that can actually reliably use it as a primer for fire explosions instead of a detonator. The Vorcha and Krogan Soldiers rely on priming FEs with Flamer and Inferno Grenades, and the window in which Carnage primes is too short for Kroguard to make use of it. So this guy can set off max level FEs, really quickly. Frag grenades are a really good detonator because they're grenades and don't run off cooldowns, meaning you can get through the short window of opportunity and set off big explosions on targets. Most people have only seen Incendiary ammo FEs so they aren't aware of just how devastating a max level combo is to armour. A Carnage-Frag combo will deal in total around 6000 damage. This is damn near half of a Gold Brute's HP and more than kills a Dragoon outright. It wipes a couple armour bars off an Atlas with each hit, and unlike incendiary ammo it's not bugged so you can do multiple combos in quick succession. You can then throw a second Frag Grenade while waiting for Carnage to come off cooldown to do another 2500+ damage before launching into your next combo. Pretty devastating. And this doesn't even factor in the additional DoT that's supposed to happen with a Fire Explosion, but supposedly that's bugged.

So that's for bosses. For low-level enemies, you can use Reegar with incendiary ammo to prime, then either Carnage or a grenade to detonate. In fact, you probably don't even need to bother with combos on mooks, the Reegar melts everything that's not armoured anyway. The Reegar also provides your shield stripping abilities, which is why Frags are spec'd for armour damage instead. The attachments I used in the build generator are not definitive; if you don't like the Reegar's low spare ammo count you can swap out the barrel for the extra capacity mod, but seeing as you're a grenade class, I would argue spare ammo isn't a necessity if you're going to be frequenting the boxes anyway. Shredder Mod is a must though. I would recommend taking weapon damage in the last rank of class passive over more cooldown increases for Carnage just so you don't have to reload to strip everything's shields.

Because frags are pretty central to your boss killing ability, I do not recommend taking Shock Trooper gear over Grenade Capacity V, you will need to have as many grenades at your disposal as possible. You could take Max Grenades at rank 5 instead if you feel 7 isn't enough but you'll be missing out on that delicious bleed damage, and any DoT effect is worth getting.

So in short, we're stressing diversity in our soldier class and finding a cool niche for the BF3 kit to fill instead of being just another AR guy.

Leave feedback, comment etc. below. Don't dismiss it just because we're doing something different here! BF3 soldier isn't a completely useless class.