No, a 9mm bullet, or any other object with mass, cannot travel at the speed of light. According to the theory of special relativity, as an object with mass approaches the speed of light, its mass would effectively become infinite, and it would require an infinite amount of energy to accelerate it to that speed.
Furthermore, even if it were hypothetically possible for a bullet to travel at the speed of light, it would not behave in the same way as a conventional bullet. Special relativity predicts that objects with mass cannot reach or exceed the speed of light. At speeds close to the speed of light, objects undergo significant time dilation and length contraction effects, which would drastically alter their behavior.
In practical terms, the behavior of matter at or near the speed of light is far different from our everyday experience. Therefore, the notion of a bullet traveling at the speed of light and being able to penetrate tank armor does not align with our current understanding of physics.