I got 1 instance of this technique on 8 Oct 2013, the day it came out. I have been using rifles on and off since then and have not gotten a single other instance until tonight (52 days later!).
Hat: festive knit hat
Weapon: achromatic rifle
Offhand: heavy riot shield
Shirt: dual armored vest
Pants: achromatic slacks
Gadget: black tablet shard
The only round of the fight:
You dodge away from the lake serpent, but still present a relatively easy target.
The lake serpent lurks under water, waiting for an opening.You catch her with an explosive round. It deals 23 damage.
The lake serpent slams her tail down on you dealing 2 damage.You slot a long clip and fire a stream of ammunition into the lake serpent, emptying the clip in a single wild spray. She takes 38 damage.
You compensate for your automatic fire, continuing the tight stream of bullets hammering into the lake serpent for 51 damage.