I suggest reading the warning on most every box of U.S. shotshells saying to shoot them only in modern guns that were originally chambered for 2 3/4 inch. Ithaca NID's are not modern and you don't really know about the length of the chambers. Better to follow the warning of the shell manufacturers than amateur opinions on the www. The RST brand shells are made in 2 1/2 inches and they are low pressure for guns like NID's.