This topic was covered on here before:
"Rifle Country" started by Catshooter, Nov 1st, 2006
Title: "Converting a Lithgow .303 to 7.62x54r"
So, there has been some interest in doing this, but if it was up to me, the bolt on the Enfield just doesn't feel strong enough for stout loads of 7.62x54r.
Could be wrong, but that's my gut feeling.