What bigcountry said is correct. In a nutshell, you're not overworking your brass with the sizing die. But that option is up to you.
As far as accuracy is concerned, this may or may not be a large contributing factor. Such things as proper bedding, a good trigger and good optics along with quality ammunition are essential. There are many other protocols inthe quest for accuracy and/or precision such as weighing and matching cases,weighing bullets, weighing individual powder charges, cleaning primer pockets, case trimming, bullet seating depth, etc., etc., that help contribute to accuracy/precision. It just depends on the degree YOU require.
Hope this has helped...............