FX Impact barrel temp after rapid fire.

Was at the range today and rapid fired a string of 20 silhouette as fast as I could and hit all of them in decent time. I touched the barrel was surprised that it was so cold. I'm used to center fire rifles and if I shot 20 rounds this fast I would have burned myself. I intend to go back out next week and shoot fast and see if the temp of barrel changes impact of pellets. 

Anyone ever noticed this and what effect did it have on accuracy ? Just curious