The two ammos I use are squad incendiary and squad disruptor until I max out warp, then i use squad warp ammo. I prefer playing as a soldier, I just prefer guns. I just wish you could embed more biotic abilities into shepherd like the first game. I never use the heavy variations of any ability as wider damage or more guns with an ability the better.

Guns I use are the heavy assault machine gun, the sniper with 13 bullets when maxed out, the 50cal once I get it, and the Geth Plasma shotgun. Oh and that pistol with the laser sight is damn awesome too.

At the end of the game I had 2/2 geth shields, and maxed every gun. And max biotic or tech mattering who I used half the game. Final battle I use Tali and Thane since they are weak and hell and so I can beat the game with no one dead. Every other mission I use Jack (maxed shockwave) and Garris, unless its a loyalty mission. 

You are an incredibly sub-optimal player.

Like, even though I know you're not playing on Insanity, that's really far from ideal.

Try using Heavy Disruptor Ammo and Inferno Ammo, then Squad Cryo on your friends. You will be terrified by how much more efficient you suddenly are.

But playing sub-obtimal makes the game much harder and more fun. Forces you to be accurate as hell with you guns. I quickly learned to headshot with my pistol efficiently. I can headshot easier with the pistol than my sniper rifle at long range.

If you cared anything about challenge you would be playing a class that isn't Soldier, and you would also be playing on Insanity; you are doing neither. You just don't think very hard about the choices you make. And that's fine, but you need to know that it's sub-optimal and you're not in a position to make recommendations about what is efficient or what isn't.

I went with recommendations others gave me actually. Minus my selection for class as I just love my guns and almost always play as a sniper in all shooters. Many people I know went with similar combos or cryo ammo and disruptor. Always the squad variation though. Only thing is I'm one of the few that bought the additional weapons pack with the Geth Shotgun.

Just like the squad and selections during the final missions were the most recommended squad and selections.  Firesquad 1 - Garris Tali. Firesquad 2 - Garris Samara. Escort back - Mordin. Final squad Tali Thane as they are the weakest in the squad, but Tali's combat droid is useful for turning enemy's attention so they can be killed quicker.

You are an incredibly sub-optimal player.

Like, even though I know you're not playing on Insanity, that's really far from ideal.

Try using Heavy Disruptor Ammo and Inferno Ammo, then Squad Cryo on your friends. You will be terrified by how much more efficient you suddenly are.