Your method for calculating depth to the lands is fine, but based on the (not insignificant) length compared to SAAMI you have a deep chamber
No it is not at all. Measuring to the tip of the bullet (COAL) is totally useless because bullets vary in length to a great degree. The ONLY way to accurately measure the seating depth is via the ogive.
COAL is the most useless piece of information ever applied to ammunition. The only thing it has any relevance to is the rounds fitting in a magazine. COAL can vary wildly depending on the bullet weight and shape. Loading to a COAL is friggen stupid.
What exactly does COAL and bullet seat depth have to do with the chamber depth (headspace)?
I also note the OP has managed to measure a number of fairly irrelevant dimensions to a very high degree and yet didn't even mention sizing the cases to the correct headspace ... something that is kinda important.
I use the Speer data, although it did not have HD powder on the list. It listed Winchester 760 which originally was listed at 61 Grains min and 65 to be the Max.
Sorry, am I to understand you used the data for one powder to determine the charge for another powder?

Are you completely insane? IF this is true you need to pull all those bullets and then sit down and have a long hard rethink about this reloading thing cause otherwise you are gonna blow yourself up. Just to be clear, 60,000 psi explosion is not something you want to experience right in front of your face.
Yes, they fit the mag and chamber without issues. I am at the max length I can go with just a little bit of space left .003
LOL. Good lord, you really need to rethink this whole reloading thing.
Get the proper tool to measure bbullet seating depth, then seat a few bullets with your press / die and see how much variation you get. Guaranteed you will currently have some that are into the lands, some touching the lands and some just back from the lands. You should be shooting for no less than .010" to .020" from the lands.
Everything I purchased was suggested by the retailer.
Then, your retailer is an IDIOT and you should find someone else.
