Various, Encyclopaedia Britannica, 11th Edition…
“ To remove a partially filled belt, the crank handle must be pushed over, thus freeing the extractor from the belt, and the latter withdrawn after pressing a spring catch under the feed block which releases the pawls. The gun now has two live cartridges in it—both in the extractor. Letting go the crank handle, one of them is deposited in the ejector-tube, and again pushing over and letting go the crank handle does the same with the second.Fig. 13 shows the feed-block and the cartridge belts. The greatest number usually carried in a belt is 250. ”
