RE: Remington Wingmaster
I believe that it can be converted to 3" shells. It involves milling the trip point for ejection 1/4" farther back and replacing the ejector spring with one designed for 3". I think absolutely everything else is the same between 2 3/4 & 3" recievers. You would need a 3" barrel too or all this work is moot.
I used to see ads for a company that does this conversion.
It cannot be converted to 3 1/2" though.
You are better of just buying a 3" to begin with (or 3 1/2").
Bob