Which action type does NOT require a separate mechanism to load bullets?

The semiautomatic action type is designed to automatically load the next round into the chamber after firing. This means that once the shooter pulls the trigger and the gun fires, the energy from the fired cartridge is used to eject the spent casing and chamber a new round from the magazine or feed system. Therefore, it does not require the shooter to manually load each bullet after every shot, distinguishing it from other action types that necessitate some form of manual loading or operation between shots.

In contrast, the revolving, pump, and break action types involve manual mechanisms that require the shooter to engage in loading or cycling between shots, either by directly moving a mechanism or manually opening the chamber to load the next round. This makes semiautomatic firearms more convenient for continuous shooting without the need for manual loading after each discharge, which is the key factor in this question.