Stevens Model 240 .410 O/U shotgun

Question
I had this gun given to me and was told that I have to have special ammo to shoot it.  Is this true? And if it is what do I need to look for?  Thank you in advance for any help you can be.

Answer
Hello John. I own one of these myself and the research I have done on it simply states the .410 will handle the 2 1/2 or 3 inch shotshells. The proper length of shotshell should be stamped on the upper barrel. I hope this helps answer your question and thank you for asking for me. Charles Gage