I can't tell ya what powder they're using in their factory loads. But if ya need any load data just ask. Some of the best powders I have found are RL 22, IMR 4831, H 4831, and H 4831sc.
You will never know what powder they are using! For the most part they really don't know either.
They may change to a different powder when changing to a different bullet with in the same caliber.
All their powder's are blended in hugh batch's and as far what kind it is, that is not their concern, just as long as they know what the burning rate is.
As I remember When the 7 Mag first came out there were no sutable powders on the reloading market. The powder in factory loads was a non canister 7828. Shortly after it was on the market as a canister ( blended for consistancy) 7828.What they are loading now is any body's guestion.???