H4350 is a very flexible powder. Think about this, you can use it in everything from the 6 Dasher thru .300WSM and almost everything in between! So the competitive shooters can use it in a wide array of cartridges not to mention all the hunters who use it in their rifles! With such a wide ranging use, it's no wonder there is a shortage!
Hell i'm gonna have to give a +1 on that.