A piece of useless info, but I find interesting nonetheless. Before Warren Harding became President of the United States, he managed a newspaper called "The Star" of Marion, Ohio. Some of the boys that carried the newspaper would become hoarse when shouting out "The Star!" as they delivered. So Mrs. Harding "obtained a supply of whistles that had been made of Krag-Jorgensen cartridges used in the war with Spain. Each boy was armed with a whistle, which made a very peculiar sound. After the whistle had been used for a while, all hoarseness had disappeared." This came out of The New Success magazine of January 1921.

(You need to Login to view media files and links)

I wonder how they did it?

From Comfort magazine, November 1898, is this reference of making bullets whistle when fired:

"Quite a consternation has often been made in the enemy's camp by the use of 'whistling bullets.' By cutting a slit and raising the tongue from the side of a bullet it makes a sharp, whistling sound as it passes through the air. The uninitiated usually seek cover when they hear these little birds sing for the first time."

(You need to Login to view media files and links)