Well here is my two cents...
I am now shooting Remington 209-4's which are no longer made by Remington. I called a factor tech and he said that the new 209 STS was suppose to be an all-around 209. He did not say that they were thinking of producing anything new.
Winchester, who ever that is today using Winchester's name, is making a ML 209 primer but they are expensive - to expensive-> someone said $4.00/100
Just as a side note - I shoot a lot of trap and I use a Cheddite 209 primer (they are cheap and laquere sealed), I really do not know where they fit in the heat range thing, but prior to buying a brick of Remington 209-4's last year; that was what I used to shoot my ML's with. During that time and even now I do not have a problem with the dreaded "crud ring." When I run out of Rem's I am sure i will be back to shooting Cheddites.