Batista shipment were found on the bodies of guerrillas. The final Artillerie Inrichtingen design is known as the Portuguese model AR-10. This final version incorporated all that had been learned to date about the AR-10, including infantry service rifle and field test reports. In addition to a heavier barrel with chrome-lined chamber, optional bipod, and the removable plastic/metal handguards of the Transitional model, the Portuguese variant had wider bolt lugs, a stronger extractor, a new simplified three-position gas regulator, and a cocking handle featuring a forward bolt assist. It is believed that approximately 4,000-5,000 Portuguese variants were produced; nearly all of them were sold to the Portuguese National Defense Ministry by the Brussels-based arms dealer SIDEM International in 1960. The AR-10 was officially adopted by the Portuguese paratrooper battalions (Caçadores páraquedistas), and the rifle saw considerable combat service in Portugal's counter-insurgency campaigns in Angola and Mozambique. In U.S. Army tests at Aberdeen Proving Ground in November 1960, and later in Portuguese service, the AR-10 gained a reputation for accuracy (some rifles would group into 25 mm (1 inch) at 100 meters with service ammunition). Portuguese paratroopers found the AR-10 to be not only accurate but reliable in combat, despite rugged service conditions in African jungle and savannah. A few Portuguese and Sudanese model AR-10s found their way by various means to nearby African countries; in Chad, the AR-10 was much appreciated by members of the French Foreign Legion. As one police instructor in the Congo stated, "It was a good combat weapon that never failed me; a bit too long (but not as bad as the FAL or M14) for house-to-house work or really heavy brush, but great for 400-800 meters, in the flats - and really nice on the body, after wandering around 12-14 hours looking for bad guys." Some Portuguese-model AR-10s were fitted with A.I.-modified upper receivers in order to mount 3× or 3.6× telescopic sights. These rifles were used by marksmen accompanying small patrols to eliminate individual enemies at extended ranges in open country. Other AR-10s were used by the paratroopers in a secondary role to launch rifle grenades. The AR-10's built-in gas cutoff design enabled it to fire Energa rifle grenades without adjustment of the gas system, and the self-loading action would even eject the spent blank shells and load the next one, allowing several grenades to be quickly fired. The added recoil took its toll