You sure you're looking at the muzzle and not the muzzle brake? On my CFX, the muzzle brake extends over 2 inches past the end of the barrel. And of course, that isn't rifled. That said, it does look like my barrel isn't rifled for the last 1/4 inch or so either. Hard to say for sure without pulling the brake off. But if so, it doens't seem to affect how my rifle shoots. Two guy that would know for sure, Bob Werner or Rich from Mich, aka Peterdragin. I know Rich is recovering from shoulder surgery, but he might still be able to answer your question. HTH and good luck.
Dave