It should take between 200 and 300 hits to make a kill;

In AlphaFFA i was making kills on 30kA cashers with 850k pop in about 240 hits for ones with low def (1:1 turrets:pop) and about 275 hits for ones with high def (5:1 turrets:pop)

Smaller countries of course go faster; 225 hits for a medium sized farmer with decent defense for example.

Something with no def that is small or medium could come in well under the 200 mark.