Today at the firing range I was shooting some .270 loads as an experiment. I loaded 10 rounds exactly the same except five had no crimp and five were crimped with a Lee factory crimp die. The five with the crimp impacted slightly more than an inch low. I thought the crimp would raise pressure...which would raise velocity...which would raise the impact point. So here I sit wondering WTF. Am I missing something here?

The crimp changes how long it takes the cartridge to release the bullet, and that changes the point in the barrel whip arc that your bullet exits the muzzle. The shift could as easily have been up, or left, or right.

I GOT ALMOST THE SAME RESULTS ONLY 1" LOW AND LEFT
ABOUT 3/4" WITH HORNADY 139GR IN 7MM REM MAG!
GUESS IT IS THE PRESSURE AND TIMING THING TO THE
BARREL. CANNALURES WITH CRIMPS MAKE A DIFFERENCE
BUT COULD BE EASILY RESIGHTED FOR. BLR7

The real question is, did the crimped loads give a better or worse group?? If better, then crimp them and rezero your rifle. If worse, don't bother with crimping in the future. If neither better nor worse, then don't bother with crimping in the future.