So I cant see any other forum posts looking at this particular upgrade, which is surprising since it appears to be the cheapest missile/torpedo printed yet (appears to cost 2).
From counting fuzzy lines of text it appears to have the standard:
"Attack (target lock): Spend your target lock and discard this card to perform this attack."
Additionally the fairly standard stats of 3 attack die and range 2-3
the only other part of the text that I can make out appears to be the number 1.
Additionally there appears to be 3 of this particular upgrade in the Rebel Transport box set as well.
From the Wookiepedia page on the Flechette Torpedoes it states:
The projectiles were loaded with jagged bits of durasteel packed around a core of conventional explosive. The shells would detonate and in effect become a debris field for incoming TIE Defenders, not equipped with particle shields to defend against material objects. Not only did the New Republic forces use them to destroy enemy ships, but to track those TIEs which survived the battle. The escaping fighters actually had debris from the flechette torpedoes in their titanium-reinforced hulls, and this debris contained hundreds of thousands of solid-state transponders triggered by a very specific subspace signal.
This would lead me to believe that it might have some sort of shrapnel effect perhaps?
Or possibly an ongoing target lock on the hit ship for all of your ships?
its hard to speculate when the cost of the upgrade is so low but I would like to hear what anyone else thinks it could be.