Aden 25mm
Engines,
with all due respect I can only recount what I heard & saw !
It did indeed spit it's innards out at the gun butts - though I am aware there was a snag with the pod design too.
Link strikes caused a lot of ( probably uneccessary ) worry as carbon fibre was regarded an unknown quantity - so the ( metal ) aft fuselage of ZD319, the test GR5 involved, was painted white to show strikes and 'my' cameras pointed at the composite tailplane, which was the real area of concern.
I don't remember link collection on that gun, only for the Swiss Hawk 30mm Aden - seems the 'green' Swiss are happy to spray shells around but not links & casings !
The gun didn't ever consistently work properly as far as I remember - there were also 'discussions' about the method of shell counting used by Instrumentation, most people thought acoustic recording would have been better.
It didn't work, which seems to me to count for 'lemon' status, as rather obviously evidenced by the fact it never got into service - the big question should still be " what are we going to fit instead ?"
It's unfortunately convenient weight - wise to discard a gun ( or two ) when already hot & high - even if it would be jolly useful !