This was an underlever taploading .22 cal military trainer, made in Germany by Anschütz in around 1954 and sent to the Egyptian army.
They were training aids for the Swedish-designed Ljungmann automatic rifle, which was manufactured under license in Egypt (source: Mike Driskill). Many examples were reimported to Europe and at least one large batch brought to the US in the 1980s(?), where they were sold cheaply.
It was common to find they had sand in the cylinders and the walnut stocks were often in a dented, battered condition, consistent with having been maltreated by military cadets.
Many Hakims have since been restored and they now command high prices. It was a long, heavy air rifle, of good quality, although some manufacturing quality issues have been identified. But they seem to have been very hard wearing considering the use they were put to. Some examples seem to have escaped the usual wear and tear altogether.
They had lead weights in the butt and fore end of the stock, which explains the overall weight.