On June 28, the American Boeing Company and the Norwegian company Nammo successfully tested their ram-powered 155 mm shells in a test conducted in Norway, and the ramjet engine of the shell was successfully ignited, which was part of the U.S. Army's XM1155 program, with a range of 70 kilometers when fired from the 39 caliber M109 howitzer and about 150 kilometers when fired from the 58-caliber M1299 howitzer, in order to achieve the purpose of the US military to suppress the Chinese and Russian artillery. When it flew out of the muzzle and flew in the air, air entered the combustion chamber inside the shell and mixed with solid fuel and discharged from the rear of the shell, thus continuously advancing the flight of the shell, the initial speed of the new shell reached more than 1513 km / h, and the ramjet engine was able to increase its maximum speed to Mach 3. According to Namo, the conventional 155 mm/52 caliber artillery system has a maximum range of 40 km and a fire coverage area of 5,024 km2, while the range increased to 100 or 150 km after the use of stamped range-extended shells, with a fire coverage area of more than 31,415 km2, and can also replace explosives with sensors or electronic jamming devices.
The disadvantage of the new shell is that the charge is slightly less than that of conventional shells, about 6 to 7 kg, the shell power is poor, and in order to solve the problem of reduced accuracy after long range, the shell uses GPS/INS-guided ballistic correction fuze, the round probability error is less than 30 meters, the cost is higher, and its canard-type control wing will increase the radar cross-sectional area, which is more easily discovered by the enemy's anti-artillery radar.
