Carl Schwamberger wrote: ↑01 Aug 2020 18:06
Rereading this thread does remains me of a couple items concerning dual purpose artillery, from long before WWII. The first was a article in the US Field Artillery Journal previous to 1925. A Captain involved in the T7 cannon project described how the development of the carriage, sights, and related items were for three roles, as a field artillery weapon, as a AT weapon, and a antiaircraft weapon. The second item comes from Gundmundsons book 'On Artillery', where he has a few remarks about interest in multi role cannon interwar, and reference to a written item circa 1932 from a Austrian Army general arguing for the adoption of a "Tank und Flieger" cannon. This TuF artillery piece was to be used as a light indirect fire weapon as well.
What all this suggests is the idea of using medium caliber AA or field artillery cannon as AT weapons had been in circulation since the early 1920s
Which article is that Carl? The 75mm Gun T7 project was the 75mm Gun T6 modified with a semiautomatic vertical sliding breechblock, which was later standardized as the 75mm Gun M2...in 1941.
I think you are thinking of the the 75mm Gun M1 (M1923E1) on Carriage T2 and T3. See Major Gladeon M. Barnes, “Divisional Artillery in the Next War”, The Field Artillery Journal, Vol. 20, No. 3, May-June 1930, pp. 240-251; Captain Elmer C. Goebert, “Modern Divisional Artillery”, T
he Field Artillery Journal, Vol. 20, No. 4, July-August 1930, pp. 359-370. The T3 Carriage was rejected and the T2 Carriage modified as the T2E1, but the 75mm T2E1 Gun and Carriage (All Purpose) failed testing in 1933-1934. However, the designer was not deterred. "Field Artillery Notes",
The Field Artillery Journal, Vol. 22, No. 1, January-February 1932, p. 120; Major George D. Shea, F.A., An Investigation of the Advisability of Further Development of the “All Purpose Gun”, with a View to its Employment Against Mechanized Forces, Aircraft, and the Usual Ground Troops, (Fort Leavenworth, Kan.: The Command and General Staff School, 1936). The best modern look at Ordnance’s interwar gun development is Major Wallace J. Savoy, “The Evolution of the American Modern Light Field Gun”, MMAS Thesis, (U.S. Army Command and General Staff College: Fort Leavenworth, KS, 1978).
BTW, do you notice who the designer of the T2, T2E1, and T3 (All Purpose) Carriage was?

"Is all this pretentious pseudo intellectual citing of sources REALLY necessary? It gets in the way of a good, spirited debate, destroys the cadence." POD, 6 October 2018