I think the game is relatively consistent within itself, though simplified for the sake of gameplay.
Taking your example, creating a new graphic and description and potentially blueprint for what then amounts to be exactly the same thing we have now is.... just not economical.
Likewise, the game abstracts the bullet length, leaving only diameter.
As was already discussed in prior threads, there are weapons of nearly every type in every calibre, I think we are all aware that they still wouldn't use the same bullets.
We have to give a system a little leeway where people can project fire and electricity with their minds and a society has been living completely underground for who knows how long, with little indication of where air comes from, f.Ex.
It is very unlikely anything will change, taking your example again, about the weapon calibres, 'sides balance fine-tuning. It makes the game more complicated while being a detriment to gameplay.