Because of the scarcity of anti-tank and field artillery in the Romanian Army, there had been felt the need for a type of weapon to replace the losses and supplement the existing equipment, that could be built in Romania with the available industrial capacity.
On June 2, 1942, a meeting between the representatives of Technical Department of the Army Ordnance Ministry and of the General Staff had been held. There had been issued for the first time the proposal for an anti-tank gun able to be used also as field artillery, and a report had been requested.
According to the report made by Col. Valerian Nestorescu, Chief of Artillery Material Service, the project could not be an entirely new design(which needed expensive, complex and time consuming calculations and experiments), but a mixture of the best elements of the guns in service with the Royal Romanian Army and of the captured Soviet equipment, whose manufacture had to be based on the tooling and machinery in service, with Romanian standardized elements and alloy formulas.
The team designated to perform the research and build the prototype was composed of Col. Nestorescu(the boss), Dipl.Ing. Lazar Stoicescu(chief of the Construction Office of the Resita Works), and Capt. Eugen Burlacu. This team had to work in cooperation with the Resita Works, who had gained valuable experience in building the AA gun "75mm Vickers-Resita Md. 1936".
To this team had been assigned for research a series of guns already in service with the Army, and also three types of captured Soviet guns(Model 1936, 1939 and 1941).
At the Resita Works have been produced three prototypes of AT guns by combining elements of the AT guns Model 1941 and 1936(Soviet), of the AA gun Vickers-Resita Md. 1936 and of the AT gun PaK 40(German).
1st prototype had a barrel copied after the Soviet ZIS Model 1936 AT gun but rebored at 75mm, firing Vickers-type shells.
2nd prototype used a barrel and muzzle brake from the Putilov Model 1902 Soviet field gun, rebored to 75mm and mounted on the carriage of the ZIS Model 1941 At gun.
3rd prototype used the muzzle brake, recoil cylinder, firing system and carriage from the ZIS Model 1941 gun, barrel, rifling and cartridge chamber from the Vickers-Resita gun and the shell chamber from the PaK 40 gun, with the other elements built locally(AT sights, panoramic sights, shielding etc). The shell for the gun was a special construction, type "Costinescu", combining the German PzGr 40 with Vickers cartridges.
During the summer of 1943 had been made various tests of the three prototypes. The barrel life, on the 3rd prototype(officially known as "DT-UDR Nr. 26, Md. 1943") was rated as 500 rounds.
In September 1943, in the Suditi firing range, a large-scale test has been organized. The three prototypes had to compete against the ZIS Model 1941 Soviet gun, the 1902 Putilov rebored field gun, and four AT guns type ZIS Model 1941 in 76.2mm calibre, built/copied by Resita Works.
On October 23, 1943, on the same firing range, in front of Marshal Ion Antonescu and other officials, the tests had been repeated, using eight armor plates, all of 100mm thickness. Four of them had been placed at 30 degrees and 300m, next three at 30 degrees and 500m, and the last one at 1000m vertically. The third prototype("DT-UDR Nr. 26, Md. 1943") penetrated all the eight plates.
Following those tests, the mass production of the gun based on the third prototype had been decided, together with the mounting on the Romanian-designed SP gun "Maresal" chassis of the same type of gun.
On December 10, 1943, an order for 3500 examples of the gun had been placed to the factories "Resita", "Astra-Brasov" and "Concordia" Ploiesti. Even from November, the Resita Works had already delivered the blueprints, tooling and specialized personnel to the other two factories, the production beginning almost immediately.
The gun was also known as T.A.C. - 75 - Nr. 26, but most oftenly called Resita Md. 1943 cal. 75mm.
216 examples have been built until the end of 1944, when the production was stopped by an order from the Soviet occupants and never revived.
In tests, the Romanian design had proved itself superior not only to the German PaK 40, but also to the Soviet ZIS 1941 76.2mm, which makes it one of the best AT gun designs of WWII.
Comparative data:
Type ZIS 76.2 / PaK 40 / Resita 1943
Cal. 76.2mm / 75mm / 75mm
Weight 1200kg / 1570kg / 1430kg
Barrel length 3.485m / 3.71m / 3.625m
Rifling length 2.57m / 2.852m / 2.5m
Elevation -5deg to +35deg / -4deg to +22deg / -7deg to +35deg
Traverse 55deg / 65deg / 70deg
Fire Direct+indirect / Direct only / Direct+indirect
Number of elements 610 / 1200 / 680
Muzzle velocity 725-745m/s / 770-990m/s / 840-1030m/s
Shell weight 6.7-6.4kg / 6.8-4.1kg / 6.6-4.1kg
Muzzle energy 175t / 205t / 235t
Max range 12km / 10km / 12km(up to 1.5km effective penetration with AP shell)
Rate of fire 12-15rds/min / ? / 20rds/min
