It's been a while since I've been in one of those olds brake drums. BUT, also check the backing plate. If there are wear pads for the shoes to ride on and they have a ridge, the shoe might be catching on it and hanging up. Smoothing that ridge will fix that. Putting a dab of white lithium will help assure smooth operation.
To add to what Fred says about drums, turning will make sure you have a good / full and flat surface for shoe contact. Not turning your drums means that they will wear past the maximum diameter that they were designed for and you would never know! Then you will run into such problems as over heating drums and wheel cylinders being pushed past their design limits. Not pretty when a piston comes popping out of a wheel cylinder or caliper. Especially when you want to stop!
