The forge gun, the SR.
It has the perk, Outlaw, right?
Well, at long range (or even slightly more than average range), it doesn't register that I get a headshot. I mean, the enemy dies, yellow numbers float up, but the buff doesn't activate.
I think it happens whenever I get a kill when the bullets begin to experience damage dropoff, most of the time that it happens.
Sometimes it doesn't even have to get that far to not register the buff.
I think the gun is broken.
If you don't believe me, test it out yourself.