Has anybody acquired the expertise to use the B25h big gun or the yak9t 37mm for ack killing with a bit more stand-off distance?
I've hit bombers at 2k out with the yak9t gun but haven't gotten good enough with it for deacking.
It's okay for deacking. You can do it. Not from outside the ack range, but still from further out. Like any other gunnery it takes practice to develop the right mental angles and estimations. One of the easier angles is straight down, so come in 3k, dive, fire 2 rounds, loop up, swing around, reposition. Takes a bit of time, but for me the reason I don't do that is because the P-39 is utterly wasted as ground attack. It is truly a fighter IMO and I want to use those spuds to see fiery round explosions emanating from enemy aircraft. It only has 30, so if I waste 20 deacking that's all the fewer rounds I can send down-range toward enemy fighters.