still messed up like i have pointed out a while ago (when trees where anounced)
one ammo type first and the others fork from that.

what we have atm:
bullets: armor piercing
slugs: incenary
missiles: armor piercing
cells: chemical

bullets: makes sense this is the basic type (kin+seismic) without extra dmg types
slugs: not the single type but the one that is most effective against the own faction
missiles: not the single type but the one that is most effective against the own faction
cells: makes no sense at all.

so one rule for all faction ammo pls. no mixed up stuff.

my point of view is that single dmg ammo first. then this is the basic tech. adding multi dmg is higher tech.

this would result in:
bullets: armor piercing (same)
slugs: composite core (other)
missiles: sonic (other)
cells: themal (other)

alternative: but less logical...
bullets: armor piercing (same)
slugs: incenary (same)
missiles: armor piercing (same)
cells: sonic (other)