https://www.metallica.com/page.asp?id=5227 click on the bandmember to get the profile and a list of gear they use
No.. Megadeth need a little gain booster, Lead tones, Better clean tones. Chorus for clean, etc etc..
Effects used by Professional Bands The pros like Metallica dont use processors for their stuff. Usually they use processors only for practice only (as they claim: Joe Satch used KORG Toneworks AX1500, John Petrucci and Steve Vai used Korg Pandora PX4 and so on) THe sound that they get in the studio is purely from amps + racks. Like the typical Metallica distortion sound from "Kill 'em All" Album is Marshall and they later shifted to Mesa Boogie Mark II/III/IV <--- which produces the typical metallica sound. (Incidentally John Petrucci of Dreamtheatre / Liquid Tension Experiment also used them.) check this out: https://www.encycmet.com/equipment/jayhiseq.shtml (this gives a better listing of equipments used in albums) and this: https://www.encycmet.com/equipment/khiseq.shtml Most of the artists rely on racks + PA system for producing (or reproducing) the tones at stage (like gigs n concert)
Some of them use pedals on stage.. Eric Johnson, Satch, vai etc.. Petrucci uses Mesa Triaxis Preamp which gives him a very signature sound..