I did 35 years in the infantry. I've never even heard of that. When loading your mags, load them fully. If you can't they aren't serviceable. Exchange them. To check if they're loaded before putting them on the rifle you press down the top round to see if it goes down. When loading your rifle, know what state you have it in. Example, loaded, readied or unloaded. When aproaching the enemy, there's no time to wonder if your rifle is or isn't loaded. These things sound like wannabe soldiers practices.
The 3VP WO's that put me through Gun Fighter told us to load 28 rounds so that our mags would seat easier. If we had any more than that they would verbally rape us in front of everyone and make you feel about as dumb as a human being can. We also would do the bump test to ensure we counted our rounds correctly after firing a certain amount of practices.