M.Rausch , I would not be building a specalised ground attack plane just to use up ammo supplies.
When I read what you write I get the impression you seem to have the picture that months or even years of development were spent to develop the Ju 87 G. These planes were all existing as Ju 87 D-5 or 7. First it was a quick and simple field modification made by the service crews on a frontline airfield. When it had been proven as valuable tank hunter, it was perhaps the cheapest and fastest conversion any German plane ever got. These planes are no own development but just changing the armament of the standard Ju 87 D, adding armor and removing divebrakes. When the planes were factory-made additionally all bomb drop equipment and high altitude breathing gear was left away. It was the best use for the Ju 87 D, since it was already started to be replaced it as CAS plane with FW 190 fighter-bombers.
If they are so many surplus 37mm AP40 rounds after 1941, they can be used by SPW-250 half tracks to give them an organic AT self defense weapon, or in recon units.
Sorry, but this would have been the real nonsense. The 3.7 cm Pzgr. 40 made most sense to be used on distances upto 300 m, in extreme case 500 m when fired by a 3.7 cm Pak. For the 3.7 cm Flak 18 guns of the Ju 87 G the range increased a little more. It is complete nonsense to expect from (regarding combat against tanks) unprotected vehicles to maneuver in the flank or rear of enemy tank formations. Only planes could get easily enough in such favourable positions. Also the area flying units could cover was much bigger.
What you really need is organic AT firepower thats available at ALL times.
That's the reason why the Panzerfaust, Puppchen and Panzerschreck were introduced, since with these weapons you had not to flank the enemy tanks, but you could destroy them also from the frontal out of prepared positions.
The question of slanted penetration of AP-40 ammo has already been dealt with earlier in this thread...
And it was not any problem for this round to penetrate the flanks or rear sides of Russian tanks from the normal attack angles the planes were flown. Tony has shown it, the original penetration charts make this absolutely clear.
Do you have evidence to contridict this CW?
What's CW? While high velocity projectiles reduce the lifespan of a barrel, it is not any factor here. The normal life expectance of a 3.7 cm Flak 18 barrel was 8000-10000 fired rounds. So let's say the 3.7 cm Pzgr. 40 reduced the lifespan to 50% just for the sake of the discussion, since nobody has till now any real numbers of the lifespan reduction. On a sortie a gun had at best a 12-round magazine. This means 333 sorties with all ammuniton fired before you had to change a barrel. I don't think anyone can see this as relevant factor.
With regard to ammo usage there are something like 10 times as many 50mm AP/HE shells produced as specialised AP 40 shots during this period, thats rare.
The Ju 87 G fired the 3.7 cm Pzgr. 40, not the 5 cm Pzgr. 40. This round was used in masses and as shown 950,000 rounds still available on December 1943. It was no rare ammunition regarding the number of firing barrels at that time.