 To top-load, the shooter pulls the rear takedown pin, hinges the upper receiver on the front pivot pin, and loads the now exposed magazine.Alternatively, several "magazine lock" devices are available which replace the magazine release button with an inset pin that requires the use of a special tool to release the magazine, thereby, disallowing a readily "detachable magazine", to be compliant with California state firearms law.If a rifle has none of the prohibited features (pistol grip, telescoping or folding stock, flash hider, grenade/flare launcher, forward pistol grip), There are several products available on the market to configure featureless rifles.