Stoeger 3000- cycles 2&3/4″ shells but not 3″ shells. Ideas??

[Robert]

Buddy at work wants to get rid of his stoeger 3000 for $100. He estimates it is 6 years old and about 1000 rounds through it. A lot of those being 3 inch shells from hunting. The gun has been detail cleaned and lubed and still wont cycle 3 inch shells. It’s not a huge deal to me as long as it shoots the 2 and 3/4 shells consistently, although it does make me wonder if it will eventually have issues with the shorter shells. Any ideas or experiences would be much appreciated, thanks!