For the ammo dice, if you are looking for semi-thematic substitutes, you could go for the
Epic Upgrade Dice for the board game
Secrets of the Lost Tomb. They're readily available and even on sale in some places.
These dice are d12s,
but they have the numbers 1-6
twice. The '6' is an assault rifle (substituting for the cartridge in the authentic d6). The '1' is a triangle (substituting for the bullet hole/explosion in the authentic d6). Unfortunately the '5' also shows an icon, but it does show the number on the upper corner as well.
E.g.,
https://www.miniaturemarket.com/eegslt-dice01.html