I agree that's it's currently OP but if my memory serves me correct then black hammer has an increased reload perk and I personally believe that after the nerf you may as well reload. The whole point in the perk is for a free refill of the magazine after landing shots in rapid succession. 3 shots is admittedly too easy, but they could increase the base magazine size alongside reducing the time allowed between precision shots so players cannot refill the magazine as easy. I personally think that would be a suitable nerf. Shotguns can be rolled with the perk that allows for the magazine to be refilled from melee kills - would you be happy if you didn't get free shotgun shells and that came out your reserve?