The product description in the link from Amazon is incorrect this seems to be quoting the specs for a Doomlands Vagabond and not the Lawbringer, correct description below:
This powerful NERF Doomlands 2169 Lawbringer Blaster fires 12 darts without reloading from the rotating barrel with hammer-action blasting. Load up your darts from the storage capsules on the stock and drop the hammer as you let each one fly! You’ll be the fiercest protector on the battlefield with NERF Doomlands 2169 Lawbringer Blaster!
Cheapest I've seen in comparison is Smyths at £17, still £30+ in most other places.