I'm not a big fan of aluminium receivers. Especially in a firearm that you will more than likely be heating up. Maybe it's just me on that thought process but back when I was a kid, you know when I went out for Brontosaurus burgers and all, steel was the way to go. Maybe the newest aluminium alloys can stand well to the heat and pressure but I aint sold on that yet. Just have a hard time putting my trust in something that can blow my face off if it goofed up.