In California, flash hiders are considered an evil feature. So if you have one, you need to have a fixed magazine. If you don't have a flash hider, any sort of pistol grip (forward or rear), or a collapseable stock, then you can have a regular magazine release. If you have any of these EVIL features (lol) then you magazine must be fixed and must require a tool to drop the mag.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul