Saw this on accurateshooter.com and thought it was pretty interesting on real barrel life.
http://www.accurateshooter.com/technical-articles/facts-about-barrel-life/
This one is on the vibrations a barrel goes through
http://varmintal.com/atune.htm
http://www.accurateshooter.com/technical-articles/facts-about-barrel-life/
This one is on the vibrations a barrel goes through
http://varmintal.com/atune.htm