Loading and reloading your AR-15 is a simple and reliable process if you follow these steps. The tip in this video can make a huge difference between a working gun, and one you have to fix.
Dearly departed AR-15 guru Pat Rogers had a special patch he would give out to students who failed to properly seat their AR-15 mags and commenced to shooting, only to watch that loaded but not locked magazine hit the dirt.
Learn to do this folks. It matters.