Famine, My Items Can Be Upgraded

[Nail launcher lv.0: 100% (Effective range 2 meters, maximum range 6 meters; can be upgraded)] [Must-hit nail gun lv.1:... (Comes with a crosshair; effective range 3 meters, maximum range 9 meters)] As long as you continue to upgrade, the range can be continuously improved, there is no limit. What will an ordinary nail launcher look like if it is continuously upgraded? What will happen if an ordinary nail is fired at the speed of light? In a world of famine, danger comes not only from food shortages, but also from evil spirits, beasts, and even humans themselves. But it's not a big problem, because Yang Chen has awakened the ability to upgrade items.