[Basicload]

Actually the myth of never resting one's magazine on the ground was debunked several years ago and it is now taught during combat marksmanship in some of the "longer" SOF military training courses.

I'll admit that I thought that they were smoking crack when they told me to do it the first time. Kind of like thumbs forward.

The inclusion of forward grips on assault rifles has reduced the ability to use external forearm support (sandbags, etc.) and this has got more and more people going to the magazine for support. Two magazines touching the ground provides less lateral movement. The magazine supported position becomes even more advantagous during high heart rate "stress shooting" events because there is a greatly reduced vertical movement from pulse rate transfer to the weapon associated with prone unsupported or sling supported fire.

I'm not saying that its the end all be all, however when the situation allows it, I will use magazine supported position.