I was watching a Ken Hackathorn video the other day on keeping your AR ready and reliable, and he passed on a tip on loading the magazine with one less shell than max. Meaning you should only load 29 rounds in a 30 round magazine for total reliability, and of course he mentioned proper lube also. This is the first time I have heard anyone mention this theory about AR mags. I shoot a Colt LE6920 with all Magpul magazines. Any thoughts on this theory?