The invention relates to a firearm comprising one or more retractable loading system elements, specifically at least one from a loading device, breechblock carrier, or slide. These each follow a trajectory when retracted. The firearm also comprises one or more reference elements, which indicate such a predetermined position of the loading system elements along their respective trajectories, at which the chamber is opened, such that a cartridge potentially located in the chamber can be seen and/or felt, but is not ejected. The predetermined position of the loading system element is distanced to possible positions for disassembling the firearm, and the one or more reference elements are formed such that they ensure that the loading system elements can travel freely along their respective trajectories when the safety for the firearm is either on or off.