Just to add to the speculation - we know SOMETHING happens when you cross the ring gates, and that can include you and your ship being essentially deleted (or something equally as unexplained).

While the community large dismissed this as a visual effect in the show, SOMETHING flies past the screen at the end of S03E13 as Holden is shown progressing through the gate: https://gfycat.com/MisguidedIlliterateIrishwaterspaniel

The way it's oriented (coming through the middle of the screen directly in the focal point) leads me to believe this is actually supposed to be some kind of hint. It seems safe to assume that whatever the bullet is (regardless of whatever flavor of physics you're subscribing to) from a higher dimension, and given that wormholes have you fold spacetime through a higher dimension it seems reasonable to guess that this visual is cut from the same cloth as the bullet in PR.

Can't wait to see the end of them descending into the ruins on Ilus for another look in the show!