knthartter: Nothing wrong with being safe!
But also be careful of substantially reduced loads of slow powders....in the past funky things have been known to happen...
JB has written many times that modern slow powders tend to behave their "best" when loaded up to higher(but safe)pressures. I did not have my Barnes manual handy, but the Speer manual calls for a max of 75 gr H4831SC with the 180 gr bullet; you're at 66 gr..Also with H1000 they call for a max of 81 gr with the 180,and you are at 76 IIRC.
General rule of thumb is to not reduce max loads any more than about 10% with slow powders.....
Sounds like you have a ways to go and I think you have room with both powders to work up while watching for pressure along the way. If you have a chronograph I would watch vels as you work up....you should be OK
