85 mm antitank gun D-48
The 85-mm antitank gun D-48 (Russian: 85-мм противотанковая пушка Д-48) was a Soviet 85-mm calibre anti-tank gun used after World War II. It was designed as the replacement for the 100 mm field gun M1944 (BS-3). Distinguishing features of the D-48 include a very long barrel and a pepper-pot muzzle brake. The D-48 was itself replaced in the 1960s by the T-12 antitank gun.
Additional Information: en.wikipedia.org/wiki/85_mm_antitank_gun_D-48