Here are a couple of pictures of a portion of a 15mm BESA machine gun belt with cartridges from a shipment of 1500 rounds received by the U.S. Ordnance Dept. in 1941. They were intended for tests of the 15mm BESA machine gun conducted at Aberdeen Proving Ground. I assume the BESA machine gun and ammunition for these tests were supplied by Britain but the test report from which these pictures came from, dated June 11, 1941, does not indicate the origin of the test material.