SOMETHING BIG opens. Written by the prolific James Lee Barrett, directed by veteran Andrew V. McLaglen. Headlined by a gaggle of second string stars who have seen better days - Dean Martin, Brian Keith, Carol White, Honor Blackman - , this singularly lackluster addition to the over-ripe comedy Western genre finds the ageing Martin as a scallywag outlaw who embarks on a cockamamie plan to relieve a Mexican bandit gang of its ill-gotten loot before his fiancé arrives from the East. Skipping jauntily from scenes of Mexican banditos straight out of central casting being mown down by a huge gatling gun to gratuitous, bodice-ripping sexual innuendos, the movie represents a career low for all concerned. Music by Burt Bacharach and Marvin Hamlisch,