This is a really good chapter. I liked it for the two great characters that was developed fast and well to make me care about them within one chapter. It followed a good flow starting out with a quick introduction to Cario and Apollo's relationship to each other. The scene is set up well with good foreshadowing of future events.
I liked the names and terms given to the guns. They are certainly more descriptive than what I would have done, and they add a good sense of verisimilitude to the world.
Following that, we get to the main conflict of the chapter, which is Cario dealing with his the person that tormented him. It was a really well done, and Apollo's part was good, too. This part fully solidified how the two of them viewed each other.
You've built a good rapport between Cario and Apollo all within one chapter.
There are a few mistakes. For instance:
“I can blame whoever the fuck I want,” Apollo said in a low, chilling tone. “until I find out who did it.”