The world of early semiautomatic rifles is a wild, untamed one. The conventions that are virtually set in stone today as best practices didn’t exist, and a seemingly endless combination of requirements and ideas came together to produce some truly weird and wonderful firearms.
One of those was the Swiss SK-46, one of the last examples of the now-dead idea of giving the soldier the choice of using his rifle as a semiautomatic or as a bolt-action. In its time, this idea made sense: The semiauto concept surely offered a great deal more capability, but also the ordnance officials of various countries did not want to lose any capability, and wanted the weapons to feel familiar. As well, early semiautomatics were not as reliable as they are today, and the option of operating one as a bolt-action rifle in theory could give them resilience against the elements that they otherwise wouldn’t have.
Ian McCollum of Forgotten Weapons takes a look at the SK-46, which by that year of 1946 combined the outdated hybrid rifle idea with a tilting bolt; at that time a feature considered state of the art:
Most countries played around with this idea (e.g., Germany and the G.41(M)), but by the time World War II ended it was clear it was unnecessary and added complexity. The excellent M1 Garand had paved the way for the modern semiauto.