Hi, i can play master of puppets(metallica) but my rhythm playing isnt quite fast enough, my lead technique is ok but when playing all the palm muted riffs i can't quite keep up with the song, and when i can i cant last throughout the song. Has anyone any tips on getting a faster, more enduring picking hand for rhythm.
Just practice scales with alternate picking, and go all over the fretboard. Thats about the only way to get speed up.

Good luck
Just keep practicing fast down-stroking. You'll develop the endurance gradually.
It all comes down to practice. The more you practice, the better you get at something.
Quote by funkdaddyfresh
justin, that was easily the most inspiring, helpful piece of advice anyone has ever given me in regards to my musical pursuits.

Screaming Help
Someone on the Ibanez Forum wanted to know the same thing.

The solution: "Rain in Blood" using only downstrokes. Practice till you can play eveything perfect. Sounds hard, right?

Either that or play a bunch of Lamb of God stuff like "Laid to Rest." Mark and Willie use downstrokes most of the time, and Laid to Rest is done simply with downstrokes.