Three tools that help a lot for consistancy:

Dial or digital vernier calipers

Hornady Headspace gauge (multiple "calibers"/datum sizes)

Hornady Comparator (also multiple calibers)

I'm a big fan of Graf & Sons for reloading so here are links.

https://www.grafs.com/retail/catalog...productId/5376

https://www.grafs.com/catalog/product/productId/7230

https://www.grafs.com/retail/catalog...productId/7288


I also have an ancient and treasured Starrett 202 Clutch Micrometer (in the original dovetailed sliding lid wooden box) that I use frequently.

Then set yourself up a chart - I use excel - and start recording measurements. Each cartridge is a page, each page has rows for the different bullets you load and each column a different measurement. When you get one that is a good shooter make a note and then you can reset your equipment quickly to duplicate the winner (and keep track of the not-so-winners as well).