The current British cinema lurches between genial little nothing movies like The Full Monty and Waking Ned Devine and scabrous jags like Trainspotting, with time out for the odd costume epic. Lock, Stock and Two Smoking Barrels is in the scabrous mode, and I like it better than Trainspotting -- it doesn't pretend its shenanigans are revolutionary. It's about four petty hoodlums -- well played by Jason Flemyng, Nick Moran, Jason Statham, and Dexter Fletcher -- who, after a rigged poker game, find themselves owing £500,000 to underworld boss Hatchet Harry (P. H. Moriarty). Coming up with the debt, they throw in a double-cross of their own. Guy Ritchie, a first-time writer-director, sets his rumbles in London's East End, with four separate gangs going at it like a serial gunfight at the O. K. Corral. An MTV-generation Peckinpah, Ritchie stages the splatter with a hideous giddiness. He's one to watch.