So a question has come up several times recently...
Some planes (P-39) have "Heavy Cannon" SAs that say it scores 3 hits on a "6".
How does this work with the rule that says if the target number is 7+, a "6" only scores 1 hit?
Should a "Heavy Cannon" plane score 2 hits instead of 3 on a "6"?
Or should it be only 1?
I'm going to have to dig around for this one, but I thought I had read that Special Abilities don't trump game mechanics. On that basis, I'd say 1. Having said that, lots of SAs (such as two difficult maneuvers per turn) trump game mechanics, so why wouldn't Heavy Cannon? I'll dig around...
Those who don't remember their history are bound to do something or other...
The rule in itself is already quite ambiguous. There is no Faq or official clarification on the roll of 6 at 7+ rule; let alone that there is some explanation that helps us with the Heavy Cannon SA. The best solution IMO is to decide for yourself, or discuss in your gaming group.
Personally, I would say that at 7+, rolls of 6 get -1. As a result, the heavy cannon would hit for 2 instead of the normal 3.