They’re revisions to the USB standard. USB stands for “Universal Serial Bus.” In the before times there used to be different connectors and formats for sending data over wires for a lot of things. Eventually USB came along and solved a lot of problems all at once: https://simple.wikipedia.org/wiki/USB

RHEL9 and forward require v3, and the numpy in pip as of a few versions back uses either v2 or v3 instructions, so v1 is silently broke for certain workloads. FreeBSD works on it just fine as do Debian based distributions as long as you don’t need recent versions of numpy, but there’s no telling what else out there just tries to run and fails with an illegal instruction.

Most traditional hollowpoints aren’t designed to break apart into shrapnel. They’re designed to expand in a controlled manner. The FBI protocol is that it should expand after passing through four layers of cloth (denim, fleece, cotton, and something else), then penetrate between 12 and 18 inches through standardized ballistics gel.

A non expanding bullet might get double that much penetration if it doesn’t start tumbling. Projectiles designed for large, dangerous game are designed for no expansion and maximum penetration. It all depends on what the goal is.

There’s a lot of youtube where people have put that kind of stuff to the test if you want to dig. There are a few results out there that are non-intuitive. For example, a regular 38 special hollow point out of a modern revolver often doesn’t get enough velocity to expand, so the cavity will fill up with cloth and over penetrate the gel even though it’s substantially less powerful than a 9mm.

No. They keep the projectile from over-penetrating the intended target.

A jeep renegade I rented did ok

You must’ve gotten a good one.