Another gun for those mall-ninja armchair Rambo wannabes. I find it amusing that my local gun store has number of used S&W .500 mags for sale in the used bin. Most likely bought by video game players who never handled a gun in their life, but use one playing Call of Duty online, not realizing in reality there is something called "recoil" that does not exist in video games.
If this is indeed real, wait a few weeks for them to show up slightly used in gun stores, perhaps with bits of the original owners flesh still attached, sold back to pay for broken limbs.