For what it's worth - I've gotten hits but no sprites just puffs of small debris, which is a recent addition to AH. I've also gotten no sprites and no puffs but gotten kills. What I've noticed flying the Yak9T lately is that on Snapshots I get a sprite (or 2) but no BOOM. Apparently the puny peashooter mounted in the cowling is landing hits but incapable of causing much damage while the bad guy is flying between the 37MM flaming Coconuts of Death (low rate of fire on that thing compounded by different ballistics). These may be some of your problems MegaDud. Or it could be something else....
BTW, on a side note, there's nothing like killing an entire formation of B24s in one pass in the Yak9T:D
Magoo