The right load for spare magazines
One of our instructors is teaching this tip: Under-load each of your spare magazines by one round. When your spare magazines are at full capacity, there is very little give because the springs are fully compressed. This means more force is needed to send the magazine into the well. Having a magazine at one round less of capacity allows for less tension, and it will go into the well with less force. I have seen officers attempt tactical reloads with full mags, and they have had the mag drop because it was not properly seated.