I think that's somebody getting confused with the 2x mk108 gunpod.... (edit: I know that's a 2x20mm pod in the pictures but I seem to recall mention of a 2x30mm pod as well)
Haven't run into it yet. I've got the second Petrick book ordered. Dunno if I'll get the first one anytime soon though, hopefully that's not where the answer to this mystery is hidden.
Definitely NOT the mk103s and the BK at the same time.
I can't see anything fitting with the BK in the bay. Even the WB151 and MK 103 mounts look like they fill it up.
Wrongway Thanks for the pics and links. I'd forgotten about that cockpitinstrumente.de website.
I don't understand what you mean:
Anyway, with all the other configurations of gun packages that were carried in the bomb bay, two or four MG151s, two MK108s and, for that matter, just bombs, I don't see why they would necessarily omit the other guns.
If you mean why they'd leave out the "standard" guns (above the bomb bay, let's call em cockpit guns for simplicity's sake), common sense reason could be simply to save weight. Is that what you mean?
The reason I'm asking the OP question is that I don't really see how you could have BK5 + 20mm + 30mm. Either:
30mm means MK 108 (short barrel, smaller gun overall) and: they were put in one of those four positions you see above the BK5 in that last face-on pic, or in a pod like the one in my above 3d and 4th pics.
30mm means MK 103 (way bigger, muzzle breaks, etc) and: they'd have to have showed up on some pics (never seen any) or been referred to (never seen that either), or they're in a belly pod. IIRC the 190A-8 or -9 had such pods.. But I don't remember seeing these myself for the 190A, and definitely never seen yet a 103 belly pod for the 410, either in picture or in writing.