These models eventually failed to mass-produce as well, before final alterations to the M70 rifle design resulted in the AP M70 B2 (fixed stock) and M70AB2 (folding stock) models. These last two models featured a thicker stamped receiver and bulged front trunnion, which was intended to strengthen the rifle in order to make it more suitable for frequent grenade launching. These two models would become the most widely produced of the M70 series, and in turn, the most widely used model used by the JNA, as well as the other militaries and various armed groups fighting in the Yugoslav wars of the 1990s. Parts kits imported into the U.S. however, show markings that appear to contradict the final fixed stock model name. On these kits, the bulged, thicker stamped receiver model is actually the M70B1 model.