It's a bit disturbing they are associating it with a bunch of Brummie criminals.
The 'Defiant' name does keep faith with BSA's traditional naming system, which borrows names from military aircraft and suchlike. Like the Meteor, Buccaneer, Polaris, Merlin .. erm not Airspoter Mercury or SuperTen.
The Defiant was a turret-fighter in WW2, a flawed design in its intended role but successfully converted to a night-fighter when on-board radar became available.
So I would say that it will have four barrels in .303 calibre and will be electrically operated. Not a rifle, not a pistol, but a turret. Perfect for shooting from a hide, or for 'spanking' the Peaky Blinder horde.
https://upload.wikimedia.org/wikiped...k1_Defiant.jpg