As Ian suggests it may be the wiper on the body that the lens moves when the aperture ring is rotated.
Two things I'd check are: is your finger causing the hesitation? And with the lens removed, does the ring hesitate when you move it manually?
If it hesitates without the lens, try a drop of alcohol between the lens mount and the meter coupling. If i's a little dust or grime it may free up. If it improves that way but still isn't perfect try another drop. Don't flood it.
BTW the alcohol will not hurt it.