 An updated model of the AR-180 was introduced in 2001 as the AR-180B, with a molded polymer lower receiver replacing the stamped steel original.The new lower receiver is combined with the buttstock, which is fixed on the AR-180B, instead of the side-folding butt on the original AR-18 and AR-180.Other AR-180B changes include the use of standard AR-15 trigger group and rear sight parts, a straight cocking handle replacing the earlier cranked style and the deletion of the original AR-18/180 spring-loaded dust cover for the cocking handle slot.