RE: wingmaster 3" or 2 3/4"
I actually called Remington about this specific issue. Could you convert a 2 3/4" wingmaster receiver over to a 3" one.
In short, they told me the actual receiver is the same, Some of the inner mechanics are different to support a hull that is 1/4" longer. You can send your gun to them and for like $180 (if memory serves correctly) can get your 2 3/4" gun changed into a 3" gun.