Can you please supply references on the Mk103 equipped 190's? Yes I know they did tests but I always thought they were found unsatisfactory and never fielded.
I know they used twin 20 mm waffen packs but never heard of Mk103's being used.
Refine "supply references"? You yourself just refered to them and complied with your own request: no 190 was fielded with a Mk103 motorkanon. Ta-152s on the other hand... but those aren't Mk103 equiped 190s, they're Mk108 equiped 152s. Sorry if my reaction sounds a bit abrasive, I highley suspect you, like many other who try to be cool in these threads, are simpley trying to add more piss to the cherios. This information, in particular (and uniquely for Fock Wulfs), is available and already out there on the internet and in these boards. The casual idea you have that these references even readily and easily exist for our free access and upon demand is also up for suspect and a questionable source of addtiional frustration in regards to this subject.
Alrighty...
In regards specificaly to the Mk103 motorkanon, I have come across a few references that state it was tested and trialed (coincidentley, other references point out that this was during the time period that the Mk103/108 was still being refined (pre full-production) itself). As I understand, during the development/trial phase, it wasn't refined and was having all sorts of problems, some with the gun and some with the ammo. (At this time I speculate, 190 test pilots had extensive experience (and a highley favorable opinion) with the two-to-four 20mm-armed A (and early D) models produced up to that time, so the not-up-to-snuff Mk103 was looked down upon.) The option was always there for the 20mm motorkanon, and in other testing being performed around the same time, great success was happening in the 190 hangar by throwing on 20mms, external or internal, single or pairs at a time.
On paper and in 1943 Germany, the 30mm looks more attractive than the 20mm, and that follows through in the decisions/priorities that the higher-ups made in regards to trying out the 30mm on future varients, but ultimatley using the ol' reliable 20mm as a fallback (the D-12 was the unsucessful 30mm motorkanon varient, the D-13 was the "successful" 20mm backup which ended up getting the go-ahead for production while the D-12 backburnered).
The 30mm didn't start finding a place in the 190 hangar until the Mk108 came along and most the bugs got worked out, but by then and only in the form of outer-wing-mounted additions, the same as the dual-20mm waffen packs (which makes very convincing sense - if you look back into the days when they were first tossing 20mms into the outer wing positions of A-models, starting with the 20mm MG FF when the newer MG151/20 came around and fittingly for its superior ballistics and accuracy was given priority placement in the wingroots). It was the very nature of that gun position on the 190 - accuracey and reliability be damned so long as it had added enough punch to do the job in one pass. In this role, and with most the kinks ironed out, the Mk108 did much better and found some acceptance amongst 190 pilots.
It was different with the motorkanon - from what I understand, the gun being that close to the center of mass (and engine) and the aiming shooter, they expected/demanded some mild degree of balistic accuracy and reliability (like that of the MG151) but at the very least something with enough reliability to not cripple its own aircraft (at this same time Mk103s were destroying their own engines in trials, and D-9s were ALREADY earning their frontline reputation for having glass radiators).