Impact is
1.8 vs balloon
1.5 vs hull
0.8 vs armor
0.6 vs guns/engines
First pre-test, as noted, was so weak that we asked for an immediate buff to velocity and doubling the clip before we even started the actual test. Going with the initial stats would have resulted in something less useful than a Minotaur. Even with the new 300m/s velocity and 4 shot clip, it was deemed mostly useless, with any other gun being better, maybe on par with Mino.
Test 2 saw massive improvements, adding another 50m/s to the velocity. This brought the usable arc over the gun muzzle for max range shots, though the gun is not that useful at max range due to the 2deg jitter. Heavy clip helps. The AOE Shatter was doubled, and 20 added to direct impact with tester feedback of wanting to break a light gun with one direct hit. This resulted in general damage that was almost where it should be, but feeling too low to use it over other heavy guns, but disable was far too high.
Test 3 is aimed at trying to keep the disable at a decent amount, while increasing Impact to a more, well, impactful level. Option A was as close as we could get with Impact/Shatter, but it is not quite right. Switching it to Shatter/Impact seems to provide a much better match to the "cannonball smash into things, cannonball keep going to smash other things" feel we were going for, rather than the original 'tickle me beachball' feel.