Something about this is confusing me.
It doesn't really matter who makes it, there are specifications for the burning rates of propellant powders that must be adhered to no matter who actually manufactures it.
This is where some of the "surplus" powders come from, they are batches that were supposed to be, say, 2230, but do not fall within the acceptable tolerances for that powder, so that particular batch cannot be released for retail sale. The outfit that made it then has an option to sell it as "surplus" (I call it "mistake") powder. Generally this type of powder is offered with load guidelines for a few cartridges, and is sold at a substantial discount.
So, if Hodgdon (or anyone else) markets a propellant powder as, for example, IMR-4227, then it should be identical in burning rate, weight-for-volume, and granule size.
Right?