You're sizing the neck at least, and if full length sizing you're also bumping the shoulder back and sizing the die body down. If your measurements aren't showing you a change, you probably need a better caliper or don't realize how tiny the changes are or how much affect these tiny changes have. For example, you want that case neck ideally to be about .002" smaller than bullet diameter. The thickness of a piece of notebook paper is about .004"-.005". We're dealing with very small measurements; it's not carpentry.

Thank you for this illustrated guide. I am also new and will definitely make use of this method.

Glad it'll help somebody!

Forgot to add in my post about this - I made my own comparator adapters, but you can buy them from a couple of the reloading outfits. Hornady has the most common version (which used to be the Stoney Point tool IIRC) and I think Sinclair or somebody high end like that makes some too.


Here's another tip for any new reloaders - to lube your brass, dump them in a ziplock baggie (I use quart or gallon size freezer bags) and spray an aerosol case lube on the side of the bag (not directly on the cases). Shake it around a bit, and them dump them out, they're ready to size. No more mess on your hands from rolling cases on lube pads, and you can do hundreds of cases at once.