I almost agree with Hot Rod. One small exception,unequal adjustment will cause one brake to apply sooner because of the small amount of pressure generated to expand the springs. When all shoes but one wheel are touching the drums, the pressure in the system should be equal to the amount of pressure needed to extend the springs in the last wheel. So, if the loose one was a front wheel you should feel a slight tug on the steering wheel toward the tight side, but as soon as the looser one touches the drum the difference should disappear. So if you apply the brakes gently you could well feel a slight pull for a short time due to the adjustment. But never a continuous pull.
I would look for contaminated shoes, drums that weren't turned equal amounts or shoes that don't match the drum diameter. We used to arc grind shoes to match turned drums. Don't think anyone does that anymore. Sometimes just a few hard stops will fit the drum and shoe more closely and even out a new brake job.
