This is my first work. I have finished it for more than half a year. I'm very sorry for sharing this work so late. There are also some minor defects in this work that need to be repaired. For example, when a shell is fired at a large angle, the bolt will not rebound. And every time you turn the barrel to a large angle, you will hear the sound of fracture (some structural fracture) and so on. But I was so lazy, I didn't fix him.oh,by a way,that every operation key in this work has corresponding functions, except 12345678 (because I'm too lazy,so I won't elaborate on their corresponding functions.XD)