Has H4227 been Discontinued or Not?

[Contenderizer]

For months I have been told that H4227 has been discontinued, yet it keeps showing-up in current loading data. The latest issue of American Rifleman has a article about the .500 Wyoming Express and a couple of the recommended loads use H4227. I realize that it takes a while to get the stuff out of the supply chain, but what's the whole story?

1. Has H4227 been dropped?

2. Can IMR4227 be substituted at the same level of charge?

I have been avoiding purchasing H4227 (and substituting IMR4227) thinking that the supply will soon be exhausted. No sense in working-up a good load only to find the powder is no longer available.