I think its called "light automatic rifle" because the FAL's weight is comparable to something like a Garand or a FN 49. The 50.00 FAL weighs 9.4lbs and the Garand and FN 49 weigh 9.5lbs. Plus the FAL in its original metric guise has full auto capability. In comparison, a heavy automatic rifle would be the Browning BAR/Polish wz. 28, which weighs 13lbs.