I'm looking at the assembly instructions and it doesn't look like a ball-and-socket joint, it looks like it's sort of an extension of the body. Which is a very good thing, because ball-and-socket joints are the worst possible case for magnetizing wargaming miniatures (they're weakest when you're shearing them across each other, which is all the time if you're doing anything with a ball-and-socket joint).
(ADDENDUM: ) If you're asking about the tail
gun that isn't a ball-and-socket either, and it's got an extra resin cable across the back for extra magnet surface if you want to try and magnetize that bit of it.
Automatically Appended Next Post: GodDamUser wrote:with how the armour plates on its back sit.. is it actually feasible to magnetise the tail?
The hull is two solid chunks of resin; the armour plates won't be an issue.