Hey, I just remembered that there was some confusion concerning the ammo counter in this thread
but I forgot to post a simple solution I had in mind for it back then.
Let's look at the ammo counter and how it's animated:
I bet most players intuitively assume that bullets are used from the left side first, because that's what it looks like.
But if there was a simple one-frame inbetween animation, the logic would be obvious:
Bullets from right side are used first and the remaining ones move towards the right side, as if pushed by a magazine spring.
I don't know if something like this would be as simple to implement as it is to draw, but if it is, give it a go.