The same model as 9T w/37mm had a 45mm.....Yes..Antitank gun.
Rod, you're enthusiastic. I'll give you that. But you're not doing research with credible sources and it's showing in this and a lot of other topics.
Caliber alone does not denote role or purpose of a round. The NS-45 was not a tank gun nor an anti-tank gun. In fact it was mounted on the Tu-1 night fighter (which was cancelled).
The NS-45 was tested in limited numbers before the end of the war as a way to improve air to air kills. It was effectively called the Yak-9K ("K" standing for some russian word denoting caliber) and had so much force of recoil it damaged the airframes used to test it. It also could only aim the first round, supposedly because the recoil made subsequent rounds impossible to control. A short burst at maximum speed was enough to significantly slow down and destabilize the plane's flight, reportedly bursting hoses or breaking fittings in the plane as it did.
However, it did score a number of kills in the trial, notably against Fw190s and Bf109s.
It was an air to air gun.
