Perked Yak??
Yak-9UT
Yak-9U (VK-107) armed with 1 × 37 mm Nudelman N-37 cannon with 30 rounds and 2 20 mm Berezin B-20 cannons with 120 rpg, giving a one-second burst mass of 6 kg (13.2 lb). Similarly to Yak-9TK could be converted to replace the N-37 with a 20 mm B-20, 23 mm NS-23, or 45 mm N-45. Production aircraft carried NS-23 instead of the N-37 cannon as the default armament.
The Yak-9UT version was Yak-9U version serialle # 39-# 083. This was armed with 23mm NS-23 cannon (30 shells) and two 20mm B-20S cannons (120 shells per barrel). Undertaken from 8.03.45 to 29.03.45, Official State evaluation proved successful. To add to the State programme, the aircraft was tested at Air Force Research Institute until 9 June 1945. A total of 282 fighters was built between February and May 1945.