It is a good rule of thumb but not a deal breaker. In fact I like loads at 101% just a slight crush fit not sure if it makes a difference but it is supposed to help uniformity. Keeps the bullets from getting jammed backwards too.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli