To correct one thing you posted earlier: The Importance of Bullet Seating Depth | The Reloading Press
Straight from Hornady 4th Edition page 15.
"When the bullet is seated to tough the rifling, it does not move when the pressure is low. It takes greatly INCREASED pressure to force it into the rifling. As the rapidly expanding gases now find less room than they should have at this time in their burning, the pressure rise under these conditions is both rapid and excessive."
So, going over the "book max" when touching the lands is an extremely bad idea.
While creating more room for powder sounds great, and many guns shoot best when loaded close to the lands, touching the lands or even jammed. It will depend on the combination of components involved to insure that putting that extra powder in does not create too much pressure.
Loading the bullet to touch the lands or jammed, it is highly recommend that you never use a max listed load.
Comparing any of load data from a 300 WM to a 223 just won't work.
If you correctly worked up a load for 2.25" OAL do the same for one with a 2.36" OAL. Just remember that if you are touching or jammed into the lands you must lower your max load and watch for pressure signs are you go through the process.