The AR-10 rifle was developed in the United States (Hollywood California, specifically) by Eugene Stoner, but the Armalite company did not have a suitable large scale manufacturing facility to produce the number of guns they expected to sell to military forces. Instead, a deal was struck to license production to the Dutch firm of Artillerie Inrichtingen in Delft. Production would only run for about 4 years before the Dutch government shut down arms production for political reasons, but during that time the AR-10 rifle would undergo significant evolution.
Today were are looking at three examples of the rifle. First is a Cuban pattern, second is a Sudanese pattern, and third is a Portuguese pattern. These do a good job of showing the changes from the early (pre-Dutch military trials) and late patterns of the rifle, as it gradually traded increased weight for increased durability and more features.