Explanation: Of particular note in antipersonnel siege weapons in Classical Antiquity is the scorpio - generally, 59 were carried along with a Roman Legion of ~4800 men - and the polybolos. Both of these were (relatively) small bolt-throwers with massive range and a significant fire rate, with a scorpio crew being able to achieve 5-6 shots per minute, being a kind of early field artillery. The polybolos, a Greek improvement, was much rarer and only attested to in Greek use, though sometimes speculated as used by the Roman Legions - unfortunately, what we don't know about the Roman Legions still fills entire libraries.
The polybolos effectively mechanized the process of the artillery crew, allowing one man to cock, load, and fire by means of an ingenious chain-driven mechanism and an internal magazine for bolts. In a crude sense, it was an 'automatic' weapon, able to self-feed and fire as long as the operator continued to operate the chain.
I can't believe they just let people own dangerous machines like these anymore, smh. O TEMPORA! O MORES!