QBB is my favorite lmg with a permanent loadout slot. My personal setup with this gun went like this:
for perks ghost, scavenger, dexterity and engineer. i play it like a smg and works pretty good. the laser mitigates quickdraw for close and medium ranges. for ranged headshots its going to take skillful aim.
Good job and first person I have EVER heard say this was their favorite LMG, either amongst my friends list or online.
I truly think it awesome that the QBB is getting some love out there!
The QBB was my second, and least favorite, of the LMGs to get Gold. I found that having the Laser Sight and Stock were absolutely necessary. I often used Perk Three Greed as well and used the Red Dot or silencer. It is scary how many more Headshots you get hip firing with the laser sight than actually aiming for the head.
Hardcore is how I got my headshots. Aiming for the head will get you an actual headshot instead of recoiling off their head in core.
You could use the Target Finder and aim at the tip of the diamond?
I did mine using stock mainly when I have it unlocked and I think it took me 1550 kills to get my 100 headshots. Aim chest high and they should come.
The attachments I used was suppressor, quick draw, and stock.
I found the suppressor to be a must. It reduces the muzzle flash so you can actually see the head when you are firing.
And if you are really having a tough time with it try out hard core. That's what I did when I got stuck on a couple weapons.
As this is by far my favourite LMG, I can safely say this one took me the longest to do as well. You'd expect its fire rate to kick the sights to the head, but the dammed gun just kills too quickly. It took me 1500 kills before I got it gold.
Anyway, to do so, I used Stock and Quickdraw Handle, Flak Jacket and Lightweight, Toughness, Dexterity and Engineer. You could switch out Perk 3 Greed and Engineer for Rapid fire, which is what I do now.