"...s...Imbel Pac 12665 Itajuba Brazilicon Pacific Armament Corp FZ SA 7.62 C3A ..the selector shows three positions S,R,and A..."

Imported by Pacific Armament. If the selector lever does not have a projection to stop it from turning to A (for Automatic), the hammer will follow the bolt back down with a shot, effectively producing a single shot FAL. Imbel receivers are good.

For your purposes, you can shoot either .308 or 7.62 with no problems. If you are really interested in the detailed differences, Google will help.