Even 5.56 FMJ shot by a phone review YouTuber smoked clean through. https://youtu.be/VLV-4HMrAz0?t=509 Hell, in that same video, .17 HMR went through the outer panel with no issues.

It’s bullet resistant to like 9mm. Any rifle round goes straight through. This is just cronyism to boost sales for Elon.

In this context, “negative mass” is a mathematical convenience rather than an actual particle having negative mass.

Think of it more like “energy required to pull apart a matter-antimatter pair”. In the vacuum of space, the energy that created the pair gets returned when they annihilate. But when near a blackhole, it had to “burn” some of its energy to interrupt that process. Energy is mass, so the blackhole gets less massive.

Mind you this is a very basic explanation of it. It’s just another quantum whackyness of our universe.