You don't actually need a new hop rubber or whatnot, unless you got a lemon. It can shoot 70m nicely with the factory ones.
The nozzle does stay in the rubber until it hits the thing that holds the springs, that's how it is supposed to work. It needs to stay in the barrel and on the mag until the bolt (or whatever that's cycling) is back enough. Then the spring pulls it back, once out of the barrel, so it can load the next BB.