If a shulker targets a player outside the world border it will shoot out a shulker bullet, but the bullet seems to glitch through the world border and will manage to make its way outside the world border.

How to reproduce

Start by going outside the world border using the following command:

1. /tp 299999999 256 299999999

1. Then place a shulker using a shulker spawn egg inside the world border.

1. Stand outside the world border and change gamemode to survival.

1. The shulker will start shooting out shulker bullets in an attempt to attack, you will begin to notice that the shulker bullets manage to glitch through the world border and after some time make it outside the world border.

Expectations and observations

Observations: Shulker bullet can exit the world border.

Expectations: It shouldn't be able to exit the world border and should instead explode when interacting with the world border.

Notes: Discovered while testing MC-271346.