Observations:
Some people might not have realized, since they do not use certain plane types with certain ammo loads, but AH2 has new hit sprites as well as hit effects. Setting aside the GVs and talking about only aircraft effects, currently AH2 has three different hit sprites in use.
Unfortunately I couldn't get any good pictures, because currently the film viewer is broken.
*30cal/7.92mm/7.7mm
These weapons cast very small sparks, very hard to observe and verify over 400 yards. It seems these are new graphics, with much more natural color than what we used to have, but very small.
*50cal/12.7mm/13mm/20mm/23mm
These weapons use the ordinary AH2 graphics. The ivory-whitish glob.
*30mm/40mm
IMO the coolest effect ever in AH2, these weapons use high explosive effects and you can see them detonate on impact.
Suggestions:
1. I'm pretty sure it is planned to be updated soon, but would it be possible that the 20mm cannons also use the explosive bursts visible from the 30mm/40mm guns? Probably a hit effect that is almost exactly the same as 'standard' 30mm/40mm hits, but about 75% the size, would look great.
2. How about adding a little bit of aesthetic exaggeration to the 30mm/40mm hits - to differentiate the visual impact of 20mm hits and 30mm or above?
Maybe something slightly deeper in color, and an explosive burst about 20% larger in diameter than the 'standard'?
Also, the resident time on the FE is pretty short. Would it be possible to exaggerate the effect a little bit more with a slightly longer resident time on the FE?
The reason for this is, these 30mm or 40mm guns are not really common weapons to be seen in the MA, which usually requires only one hit to be lethal. You rarely see more than one burst on the enemy plane, as opposed to MGs or 20mm cannons. It seems to 'pop' and just disappear.
Thus, the short resident time on the FE makes it kind of hard to appreciate the work and effort you guys put through. The current effect resident time on the FE would be good for 20mms, since multiple volley of hits would probably throw up a cool succession of bursts and explosions on the enemy plane, but it seems a bit short for 30~40mm cannons.
So, to sum it up:
1. Enhanced graphics are needed for 'normal' 50cal/12.7mm/13mm gun hit effect
2. High-Explosive 20mm cannons should use an explosive effect simular to that of the current 30mm/40mm hit effect, smaller in size, simular resident time on the FE.
3. 30mm/40mm hit effects could use a slight 'beefing up', with slightly longer size, and resident time on the FE, to increase the visual impact and pronounce its difference to 20mm HE hit effects.
Thx for reading

ps) Oh, another thing I've observed - the hit effects don't seem to apply on ground structures. I've tested the Hurri2D 40mms, and it throws up that explosive fireball against airplanes and GVs(way cool!), but nothing much against ground structures or ships.