Summary: During the test, the sample gun was towed 15 12 km. Among them, the road test was towed by "stoddard Barker" truck1030km, and the cross-country test was towed by Ya- 12 tracked vehicle for 482km. For some reasons, Gith -D-44 failed to pass the military test, especially the projectile ejection was not smooth. In order to solve these problems, the sample gun was modified and passed the second test, named as "D-44 85mm extension gun". The gun has these characteristics: double gun valve; Semi-automatic vertical locking; The cartridge case is fully and automatically retracted; Hydraulic parking machine; Casting and molding gun racks. The sighting system includes S-7 1-7 panoramic sight, and the rangefinder has used OP 1-7, OP2-7, OP4-7 or OP4M-7 models. The night vision equipment is APN-2 or APN3-7. The gun rack contains a simple torsion bar suspension system, and the gun wheel comes from GK wheel of Gus truck. At the end of 1948, an auxiliary propulsion gun based on D-44 was developed. Its ballistic characteristics and armor-piercing force are the same as those of D-44 towed gun. The sample gun passed the acceptance on1954165438+1October1/and was named SD-44. SD-44 auxiliary propulsion gun produced 697 guns. Later, in 1947, the Ninth Arsenal tried the improved Gith-D-44A 85mm divisional artillery, which was more powerful. But it has never been mass-produced.