We know in middle school physics that the bullet can fly in a straight parabola because it rotates in flight, and the gyro principle keeps the bullet stable and will not fly around, flying according to the predetermined trajectory and hitting the target.
The rotation of the bullet is given by the rifling of the barrel. In the gun bore, there are several rifling lines, and the rifling lines are spiral. The diameter of the bullet will be slightly larger than that of the barrel. When the bullet is loaded, the warhead will be embedded in the rifling. After the bullet is fired, the gas generated by gunpowder pushes the warhead to slide forward in the gun bore, and the spiral rifling gives the warhead rotation.
In order to facilitate the warhead to be embedded in the rifling and not damage the rifling when sliding, the warhead is generally made of soft metal or armored with soft metal, such as copper, lead and nylon plastic. Some local tyrants use silver as bullets, and some use cork bullets for training. But no one has ever used steel as a warhead. Even steel-core bullets have copper outer armor. Because the steel warhead is too hard to be embedded in the rifling. After firing, it will damage the rifling and even get stuck in the barrel. Even if the bullet can be fired, it will seriously damage the rifling.
Then, in Wolf Warrior 2, if the bullet is made of patterned steel, the bullet with high hardness and serrated pattern will be like a file at high speed, which will cause devastating damage to the rifling of the barrel. Rifle damage is equivalent to barrel failure, and the barrel will be scrapped in a short time. Therefore, a normal ammunition manufacturer can't make patterned steel bullets at all.
At the same time, this patterned steel bullet is an automatic rifle bullet. The massive consumption of automatic rifles once made Japan afraid to equip the whole army during World War II. Making a large number of automatic rifle bullets with expensive patterned steel, this European mercenary group can't stand the money again.
Therefore, there are no live ammunition made of patterned steel in reality, and there will be no live ammunition made of Damascus steel.