I'll give you a more detailed explanation then.
Powder is made in bulk (tons at a time) and it never comes out quite exactly the same each time (it's like making scotch or wine
).
Each type of powder is given a type number, like W-750 (a
BULK Winchester ball powder). Each shipment of W-750 is a little different than the last.
For commercial ammunition companies, this is no big deal, cuz when they get a new load of powder they just tweak their loading machines and keep on going. That's why the cartridge you bought today will vary in powder weight (and maybe type) from what you bought three months ago, or three years ago.
But for selling powder to the public, the powder companies will "blend" different batches to get a constant burning rate.
For example, when making W-750, some of the fast batches will be held back, and some of the slower batches will be held back... and when making powder for the consumer, they will blend some of the fast with some of the slow to get the exact burning rate that they have defined for the public, as W-748.
So the W-748 you get today, will have the same burning rate as W-748 you bought 30 years ago (and it DOES!!)...
... but the W-750 that they load in cartridges will vary in weight from batch to batch.
Here in the states, a shooter can buy W-750, and work out the loading data themselves, and save a bunch of money - cuz it's sooooo cheap. About 20 cents on the dollar.
Now here's the thing - Hornady can't tell you what they use because of legal problems - they can't be responsible for giving you loading data for a powder that keeps changing it's burning rate.
The powder in their .22-250 probably is a bulk version of H-4895 or Varget (both are about the same speed, Varget being slightly slower).
With these two powders, it could be either one, because they are so close in burning rate, and they look almost identical.
Hornady could have used a slow lot of bulk 4895, or a fast lot of Bulk Varget, and the charge weight would be the SAME! So you can't tell by weighing the charge.
That's why they won't give you any information.
If the pulled powder looks like Varget, then try that - it's a great powder, and the first choice of many shooters - if you don't get the accuracy you want, then try H-4895.
Both are classic powders for the 22-250.
.