If you take a look at older (like '70's vintage) reloading manuals, the max loads are quite higher than the ones that they will publish today.
It is a pretty good idea, to take a look at as much load data as you can, and start somewhere near the middle or nearer the low end, and work your way up or down if you feel the need.
And remember that load data as presented, only represents a pretty good picture, rather than an exact one, of what the pressures will be like. They are as shown for the exact set of variables defined in the load manual (case, primer, powder, bullet) and in the chamber that was cut on the test barrel.
Cheers
Trev