Before replacing, it would do you well to test the wire to see if it works OK or not. Why replace the whole thing if it still works.
I can almost guarantee the wire in not in any kind of a conduit. If you attach a connector to the old wire and the other end to the new wire, you (might) be able to pull the wire through. But if the wire goes through any turns, the connector will catch and then you're just out of luck.
If the bullet hit the wire at the connection by the antenna, and the wire is except for that spot, you're much better off just replacing the end.