I have read numerous times that the Rum's life can be as short as 400 rounds, but this can be due to a nasty carbon ring build up in the throat area. Many people have tried to clean this carbon ring out with varying degrees of success. But everyone seems to agree it is a PITA.Pure curiosity! As I was reading another thread pushing the RUM very hard by multiple members yet everyone avoiding answering the question asked by a few. What is the barrel life difference between these two 30 cals?