I have just finished watching a Japanese video version of this film (titled Big guns) and found it very entertaining. I would recommend this Franco/Italian made movie to any lovers of the Italian crime genre,why, well for a start the great cast of Euro-stars, apart from Alain Delon there's Marc Porel (Murder to the tune of 7 black notes/live like a cop die like a man), Anton diffring, Richard Conte, Carla Gravina and Erika Blanc. Also the way the movie was executed, a familiar story (of a mafia hitman who wants to retire) but shot and paced excellently. Of course- things don't go to well for the 'want-out' hitman (Delon) and finds himself with a personal vendetta on his hands.
Great bloody shoot-outs, great car chases, sexy leading ladies (who also get ruffed-up) and a phat "Schiffrintastic" score sometimes reminiscent of 'Harry's creed'. The version I watched ran into 112 mins and was widescreen.
If you get the chance, check this one out.