I feel more inclined to believe the company that manufactures all those powders than companies that just post load data for it. there is also the chance that the formulas have changed over time slightly altering the burn rates or even variance from lot to lot. however, I'm guessing the online references that hodgdon keeps are fairly up to date.
I believe if you will get a good Chronny, you will find that even with a 16" barrel, with the bullet weight you are using, you will still obtain highest velocity with slower powders lit with magnum primers.
Sometimes stuff just happens. Shot a big doe early in the 2014 OK muzzleloader season. The bullet was the excellent .45 caliber 300 grain Hornady magnum in a crush rib sabot. The muzzle velocity of my load has been chronographed at just over 1,925 fps.
The deer was 85-100 yards from me when i fired. The bullet impacted with about 1,600 foot pounds of energy. Because of the smoke i could not tell where the deer went. Went to the spot where the deer was standing: No blood at all.
Deer was found about 100 yards from where it was shot: There was a big pool of blood on the ground. Looked for blood on the deer trail and grass between the two points and none was found. The bullet hit both lungs and a piece of bone or piece of the bullet lacerated the heart. The entry and exit holes were huge.
With a 30-30 you should be using a 170Gr. bullet to get good penetration. Of course you need to hit the target (vitals). 150Yds is a good reach for the 30-30. Get rid of the 150Gr.