I recommend 1/2 size to 1 full size from regular sizing.
It seems for the factory seconds there is an issue with the heel area inside the boot. It makes the heel of your foot sit higher in the rear slightly raising your foot into the vamp area which makes them uncomfortable but not unbearable to wear. I am sure with time and effort these will break in beautifully.
![](https://i.ytimg.com/vi/VDPL-OwExRc/maxresdefault.jpg)