So I'm running a 3080s-ish Jade Falcon armored force in my group's Tanksgiving game this weekend, and being a post-Jihad force, some of my tanks are spheroid units. Is it feasible that the Falcons would have access to House-made specialty ammo, such as Precision AC rounds? Even if they had access, would the Falcons deign to use the stuff?
The references you're looking for are on
Interstellar Operations page 59. The Clans apparently never introduced precision ammo to standard production as it's technically not part of their tech base, although it's also confusingly listed as available to PACs. Flechette and AP rounds were introduced in 3105 by the Horses and the Falcons respectively. Flak is also available for any Clan-made standard or Proto cannon. (The Clans have lighter ACs available earlier in the book.)
As the tanks you're describing are Spheroid, that gets more complicated. I doubt the Falcons have much of it but they would probably issue it if they captured it, they're pretty pragmatic, although the precision ammo might come with a sneering insult to the troops in question. I wouldn't give precision to troops who are well thought of, anyway. AP, flak, and flechette are probably not subject to the same stigmas.
Protomech AC's can use special ammos. Not sure it it is IS ammo from a different weapon or clan made versions in such cases.
It's Clan-made ammo. ProtoMech ACs don't use the same ammo as standard ACs and are a different tech base besides. I gave the dates above.