This is a 28mm scale (1/56th) model of the Soviet A-19 Model 1931 field gun gun. it is a rework of kpi1986's excellent file of the same gun.
The A-19 was the backbone of medium field artillery for the Red Army, and continued in use is different versions well into the Cold War. i did this up for use on the Bolt Action gaming table, where the gun is both a medium field gun as well as a heavy ATG.
I took the original file, separated the gun barrel and breech area from the carriage. I created an axle and strengthened the vertical hydraulic recoil cylinders and the carriage itself; detailed the wheel hubs and tires, added a hand wheel on the right side of the gun (where an elevation wheel is located) and modified the spades on the end of the gun trails.
I printed this on a fine setting with rafts. As always, be careful removing the support material. you will find the wheels fit the hubs snuggly, so clean the wheel centre out. I glued the gun to the carriage with epoxy.