The Hornady manual is also very conservative in their load data maximum compared to Sierra, Nosler and Berger.
When the litigators get too close to load data, you get some very conservative results.

Sierra uses data actually gathered on the range for their tables, list rifle and barrel length used and show load data for incremental velocities.
Hornady also shows load data for incremental velocities and it appears that they also gather their data on the range because they list the rifle and barrel length used.
Nosler also appears to use data gathered on the range but lists starting loads, an intermediate load and a max load.
Berger uses QuickLOAD simulator software derived data rather than actual fired data and shows only starting loads and max loads.
None of the manuals list the temperature at the time of testing. See page 14 & 115 of the Berger Reloading Manual.
I have no problem with that since I am a heavy user of the QuickLOAD software.
[However, QuickLOAD software uses a default temperature setting of 70 degrees (the European powder test norm), so Berger's listed velocity numbers might be a bit higher (about 1 %) than data from U.S. manufacturers that would normally be based upon a 59 degree powder test norm.]