Not quite.
Handguns were banned on the UK mainland (bar some exceptions), but are legal in NI. As is concealed carry.
Assault rifles were banned in 1988.
Rifles and shotguns are legal in the UK.
From certain cases I've read about, God help you though, if you DARE to use a rifle or shotgun to defend your life or property there however. You will go to prison and the perp--if he lives--will get off scott free--and--probably sue you.