I've worked on enough spools that should  drop via gravity through the bore... usually slowly  and steady... but a simple  finger print would hang it up! Stuff has to be about as sanitary as humanly possible here.
It's not uncommon to not see or even feel a rough spot  that would jamb things up tight.     I like to check not only the  lateral movement,  but  able to turn it with zero   'tight spots' too.