Q-tips.Use the Q-tips, put it in the barrel at the crown, turn slow and remove slowly. Check to see if any of the cotton strands gets hooked up at the crown.This will indicate a bad crown and fixing will be needed.
if you look at ur gun the barrel and breech are all one peice so that whole peice has to be replaced to replace the barrel. thats why you can either order a new barrel assembly from crosman or send out some emails to places like mellonair.com and ask if they can chop and recrown ur barrel for you.if it was me id rather have my barrel chopped by a half inch and then recrown by a pro because then i know the crown is perfect no questions asked.