>>31989
The Greeks and Romans had different shapes and sizes for different functions
>small ballistae as "machine guns" and "fixed guns"
Some of these were self loading (Polybolos) and had a fairly high rate of fire. Others (like the Scorpio) needed to be manually loaded and fired more slowly. These would have been used against infantry and would have fired bolts
>manuballista/Cheiroballistra as "battle rifles"
A handheld variant which would be shouldered like a medieval crossbow. They were comparable in power to the scorpio and polybolos
>Carroballista as "humvees"
A small ballista mounted on a cart for mobility. Were likely of cheiroballistra class
>Lithobolos as "howizters" and "field guns"
Then theres the big guns or Lithobolos. These would have launched either stones or fire pots. Some were man sized and were either light siege weapons or field artillery. Others were house sized and would have been used for long siege battles