Traps

I'm fairly new with shotguns but I removed the plug from my Nova Pump...all I did was removed the C clamp removed the red plug from spring and put the C clamp back into place. Was it really that simple or did I miss something?!!?

When loading a shell into the magazine, should the carrier fall back down behind each shell after it's been pushed into the magzine? Also, when the gun has no shells in it at all and you push the carrier up, should it lock and stay up?