Okay, so maybe you're here because you want to know the secret to getting that heavy "Metallica" guitar sound. There is a secret, actually there's a few secrets.
The Metallica Heavy Tone Picking Technique
Down pick all of the notes you play in the riffs. That's right you want to downpick all of the notes. Play Master of Puppets with only downpicking. It's not easy but that's how you play it properly. This will give you an even heaviness and make your playing more intense. Just a word of warning, James himself doesn't down pick everything, but he down picks a lot.
When you strike the strings with your picking hands make sure you hit them with the finger nail holding the pick first, followed immediately by the pick. In essence you will hit the string twice, but too quickly to hear it is a double strike. This will increase the heaviness greatly. Now try that Master of Puppets riff again playing this way.
Make sure your pick isn't thin and flimsy. You'll need a thick pick that doesn't bend easily under pressure. The thicker pick will mean heavier sound, of course
- You know you need some killer distortion, right? Well, that's not all. Make sure to use the right Metallic amp settings too. Check out Part 1 of this post.
To prove to yourself how much of a difference playing heavy riffs like this will make, try playing the riffs with and without the down picking, and scraping of your fingernails when striking the string. I promise you won't ever want to turn back.