Here we go again, and make no mistake, I do NOT want to know what the result should be, on that we all agree.
The ONLY thing I am after here is what the rules tells us, literally.
If we start with this "such", I agree it probably means weapons with no B# printed on the vehicular counter. Then it is perfectly clear what happens when such a weapon rolls a "12".
Now, we have the question about what happens with a vehicular weapon with a B11 printed on it.
D3.7 in that case do not apply as it only, due to "such", applies to vehicles without a printed B#.
A9.7 do not apply since that rule is about SWs and no reference is made to that rule in D3.7.
C2.28 would apply to such a Gun, but as we know there also exists vehicular weapons that are not Guns, for example MGs/FTs.
The conclusion must therefore be that the rules do not tell us at all what happens to a MG MA with a B11, it could be anything, including nothing.
Just to complicate matters, what if Ammunition Shortage is in play or Intensive Fire?
What bugs me so much about this is that out of ASLs 99 problems, this is the hundredth and that makes no sense.
No matter how many problems ASL has, very few if you ask me in comparison to the complexity of the game. The more we can get fixed the better for newer players. We have a real problem if we start to rate how important fixes to known issues are.
There is a easy fix to this problem that will not affect anything else, exchange the "12" for "B#" in D3.7 so it is in line with A9.7.
Oh, once again. Do NOT tell me it should malfunction, I know that should be the outcome, it is just not supported by the rules as written.