Ah, thanks. Makes sense.
I managed to implement it somewhat successful. I still have bullets passing through enemies, apparently not as many, though.
So in order to understand what's going on, I have a question: By what conditions is a collision tested?
If a bullet collides with an enemy within the repeating pattern (say at 5th repetition out of 10), does that count as a collision? Because of this was the case, moving the bullet 1 pixel would always ensure a collision, right?
The reason I'm asking is because that's exactly what I've done, then tweak the bullet speed with the amount of repetitions per tick, but as I wrote before, there's still stray bullets.
Would enlarging enemy hitboxes help?