This is my idea for a build. I use Assault Rifles, and shotguns for those that get too close. For shield I use Health Boosting. I am looking at using Rifleman COMs. I am looking for critiques and ideas for this, so please share if you have some.
http://talent.87bazillion.com/soldier.php?535055550550505050055
First off: Get Metal Storm, seriously, you won’t regret it.
I would ditch barrage for it, and then ditch Guided Missile for Grenadier (the grenade ammo regen on Grenadier makes nade spamming easy and it not only buffs their damage on-kill, but also damage of any rockets you fire, including those from carnage shotguns).
Move the 3/5 from Sentry over to Supply Drop (makes sure you never run out of ammo, and this even regens grenade ammo too).
This tree:
http://talent.87bazillion.com/soldier.php?505555050505535050055
…is pretty much standard fare DPS Roland.