I am betting they are just shooting wadded black powder sans shot, but that muzzle flash in the dark is still impressive. To paraphrase a friend who wanted to know just one thing about how Kazakh eaglers man their birds ("How do they train them not to eat their kids?"): how do they train the horses not to bolt when they fire off those rifles?* Double or right click for big.
Using "dogmeat" as a verb is as far as I know an original John Davila- ism.