Where can you get a owner's manual for a 20 gauge Ithaca model 300?

You can obtain an owner's manual for a 20 gauge Ithaca model 300 from several sources. The Ithaca Gun Company’s official website may offer downloadable manuals or information on how to request one. Additionally, firearm forums, online auction sites, and collector groups often have sellers who can provide copies of manuals. Lastly, you might find it helpful to check with local gun shops or libraries that specialize in firearms literature.