Weapons qual question?

Your 1SG was correct. There is nothing in the regulation that states you can not rest the magazine on the ground (only logic about possible jamming, which you claim does not happen to you). If your LT still claims that it is "illegal" ask him to please show you it in the regulation. If he still claims it is cheating have him do a 15-6 investigation and provide supporting doentation in regards to this vicious crime! The regulation states that the weapon can not be resting on sand bags or a ledge. As for resting on the ground how do you see down the sights?