All the manufacturers use their own type of powder. The flash that you saw today was unburned powder lighting off outside the end of the barrel. The different types of powder used burn at different rates, some burn faster than others. Barrel length also has some to do with it, shorter barrels will usually get muzzle flash when longer ones don't. Hope this helps. Muzzle flash shouldn't really matter, except when picking a defensive round to use in the house. You don't want to blind yourself if you ever have to use it indoors(hope you never have to) I hope this answers your ?