Name role of character.
There is like 4 types of gatling characters possible to create, with great dispersion of levels needed.
Traits.
Bonehead is a must in pvp. Since all snipers (you will see snipers for sure) can KO\KD\eye cripple at ease even tanks, bonnie is a musthave trait. Strange that BB. didn't mention this.
Fastshot is pretty fine since you're focusing not on aimed shots, but on heavy blows from gatling bursts or rockets.
Perks.
Weapon handling seems crazy perk, you don't need it that much. I'd recommend to take Adrenaline Rush for further tankyness, it saves asses and works fine, especially for range combat.
You can also swap one ab for stonewall. Believe me, when shit starts to fly around, it's the thing you will pray to have.
Specials.
Again, if it's a pvp-based build, you need all that luck in perception. Simply because of FoV = life, plus you'll be able to use psycho without limiting your sight that great.
Skill tags.
You can hybrid yourself pretty much with everything, there is rocket launcher\lsw from BG which you can use or XL\grenade launcher from SG. Choose youself.
Don't forget to make 100 doc and at least 175 FA. Start level bg only after getting dis.
That should be all, for tanky gatling - that's it.