A Literary Digest article concerning the skills required to survive as a sniper in World War I France:
"One extremely important rule was that he should swab the muzzle of his rifle after every shot, to make sure that no moisture had collected there. One tiny drop of water would, upon the rifle's discharge, send up a puff of steam that would reveal him to his carefully watching enemies."
To see a diagram of the American W.W. I sniper rifle, click here.
Further Reading from Amazon:
The Springfield 1903 Rifles