There is a vast difference in these cartridges and the link below covers the topic very well. There is a significant pressure variance that one should consider carefully. The Indian Enfields are built to handle about 45,000 p.s.i. As the link states, the .308 can go considerably higher and would be a stretch for a British Enfield. Hope this helps. All the best...
Gil
http://www.thegunzone.com/30cal.html