I recently aquired the monogram ac-47 gunship. I am planning to convert it to the strait c-47 wit ha full interior but the windows have huge injection rings that cant be sanded off. Are there any aftermarket windows out there?

I haven't seen aftermarket windows unless squadron/falcon makes them, but you could rather easily do them yourself with crystal clear.

John

I think those "injection rings" were supposed to represent removable sections of the windows for WW-2 vintage C-47s. The theory was, that if attacked, the troops being carried inside could stick their rifles through those sections and fire at the attacking fighter(s). So they're supposed to be there. That being said they more than likely wouldn't be appropriate for later C-47s.
You may just want to sand them off, then use a polishing set (Micro Mesh is good), or a tri-grit sanding stick (available from Squadron and others), then dip in Future. If done right you'd never know they were there.
You could also try making the windows from Micro Kristal Kleer or I've heard that Gator Glue works well as window marterial, too.