Originally Posted by Naigewron
You might be thinking of Leper Messiah. Lars counts in the song with five hihat hits ("ONE, TWO, Tssch, Tssch, Tssch, Tssch, Tssch"), but the actual song is in standard 4/4 (it's surprising how many people think it's in 5/4 based purely on that intro though). Other than that, I can't think of any 5/4 songs on Master Of Puppets.
edit: Actually, there are single bars of 5/4 in Battery, where they sing the "BATTERY" line, but no prolonged sections of 5/4.
That's probably it, then. I just heard someone talk about there being a 5/4 song on MOP
Edit: just listened to Leper Messiah again and Lars derfinately counts to five...You can hear him behind the "tssch" sounds.And he hits the hi hat five times to count them in live: (at 1:11 in this video)