Firearms

I would like to know everything about guns, frame, barrels, chamber etc. i will buy best gun for hunting.
(i have two firearms licenses for carrying firearms 01. .12 shotgun. 02. pistol.32)
i would like to do extreme long hunting so i need a professional semi automatic .12 super magnum shotgun better than remington 870 super magnum. i like to buy a shotgun a caliber: 12 gauges
action: semi automatic.
frame: best steel in the world for guns
barrels: 32’’best steel in the world for full ch