The SIG AK53 is a Swiss battle rifle.
Developed from the AK52 designed the previous year, the AK53 was an experimental battle rifle developed in 1953 by SIG. Only about 50 of these weapons were made. It was later submitted for trials, but was rejected. However, this led to the SG 510, which remained in service for three decades.
The AK53 was a flapper-locked breech, gas operated, fixed breech, select fire battle rifle that used the blow-forward action. However, it was unique in that the bolt stayed in a fixed position while the barrel moved back and forth to chamber and eject cartridges.