If you are traveling or moving to California for any reason they have some pretty crazy laws. One of the most recent ones is no more bullet/mag release button. They physically make you buy a kit to cover the button so you can't remove the mag. They want you to take down the AR and remove the mag internally. The best way around this is this fancy loader I have found on line. It is the Mean Arms (MA) Loader AR-15. Check out the link below for the video of how it works.