I use Hodgdon's web site for load data and notice occasionally it only gives max loads with the starting load column blank. What is the purpose of that?
I am wanting to work up some .44 Rem mag using Hornady 240 grain XTP's and IMR800X powder. The web site just shows max load at 14.2 grain. I know that I need to drop it by 10% checking for signs of pressure as I work up. What do you think of start at more than 10% less? Maybe 20% less than max load?

Some powders aren't safe to reduce even 10%.  H110 loads usually only list a max and the powder canister says reduce 3% and work up.

Good point!
I also cross check when loading and have several loading manuals to do that with. One thing I have noticed is that my Hornady manual will sometimes show max loads less than start loads for the same caliber/bullet weight in other manuals.
Hodgdon indicates W296 and H110 not to be reduced more than 3% due to the possibility of a bullet lodging in the barrel. I'm sure that has something to do with case capacity and pressure.

copy and pasted from Hodgdon's site:
"For those loads listed where a starting load is not shown, start 10% below the suggested maximum load and then approach maximums carefully, watching for any sign of pressure (difficult extraction, cratered and flattened or blown primers, and unusual recoil). H110 and Winchester 296 loads should not be reduced more than 3%."

Wow!! I have a hard time with 380 stuff, kind of like a bear cub wearing boxing gloves sometimes...... I'm sure the 32 stuff is hard to handle too!