In the late 1950s and early 1960s, the Dutch government was looking to adopt a new rifle for its Army, and considered both the AR-10 (which was being produced domestically by Artillerie Inrichtingen) and the FAL. The FAL won out, but it was not immediately clear if that rifle would replace everything in Dutch service, or just the front-line Army rifles. The NATRES (basically the Dutch national guard) was equipped with a great many M1 Garand rifles supplied by the US, and these was some thought as to whether it would be more cost-effective to modernize those guns rather than replace them all with new FALs.
With this in mind, two AI engineers headed to Italy to visit the Beretta company and investigate the possibility of a BM-59-type upgrade to use detachable magazines in the Garands. Being from AI, the magazine they had in mind was the aluminum AR-10 “waffle” magazine, and a couple prototypes were made using this magazine in a converted M1 Garand:
Note that the typical paddle magazine release of the M14 and BM59 was replaced by a push-button release inset into the stock, to accommodate the magazine catch on the AR-10 magazine. The guns, of course, were also rechambered to the 7.62mm NATO cartridge instead of the original .30-06.
Ultimately, this rifle never went beyond prototype stage, as it was determined that it would be simpler and more efficient to equip both the Army and NATRES with FAL rifles, rather than run two separate guns concurrently. Thanks to Vic for the photos!