May sound like a dumb question but ive got a remington express magnum in 20g that I would like to turn into a home defense gun. Since I'm poor and I dont want to go and buy another shotgun I would like to know if the stocks are interchangeable. Especially the feedspeed pistol grip type. I'd also like to put a 2 shot extension, if possible on there. Is this possible?

Remington has two different action sizes in 20g. One takes the 12g stocks and one does not. The letter at the end of the serial number indicates which size it is. Check Speedfeed's site, it tell which is which (sorry, I'm too lazy to do it myself right now). Choate makes mag extention for the 20g, you might have to get it direct from them, I couldn't find it anywhere else. Check Brownells though, I think they just added them.