The most that I did for my AR-10 and AR-15 was add fiber optic sights. I have the flashlight mounted to each, and the 10 has a nice scope while the 15 has a small scope on the hand carrying rear sight handle. I wonder where that tale of jamming came from if the magazine is resting on the ground. Oh well. But I would add that as a 68 year old, I am NOT getting off the ground, or use the kneeling position anytime soon.