In 2270 the Australian military was looking for a replacement for its aging M8 caseless assault rifles which had been in-service for nearly twenty years. Developments in rail gun technology had seen the steady demise of the caseless chemical propelled ammunition and its associated weapons and most countries had headed down the Advanced Combat Rifle (ACR) route equipping their troops with weapons firing magnetically propelled ammunition. The ACR concept enable the weapon to interface with the helmet display of the soldier giving targeting information and allowing accurate fire from relatively untrained troops. The system also allowed IFF (Identification Friend or Foe) locking to reduce friendly fire incidents.
The F50 followed a bull-pup design with a 100 round magazine and an under slung 40mm single shot grenade launcher capable of firing all the current range of ammunition including the variable timing airburst rounds, both the grenade launcher and the main weapon are both powered from the magazines high capacity battery. Unlike other countries who have added magazine fed grenade launchers to their standard infantry weapons, the Australians opted for the larger grenade size over magazine capacity giving them access to a wider variety of more powerful grenades but lacking the rapid fire of other weapons. This was thought of as a fair trade off with the increased accuracy of the ACR targeting system.