Redding competition shell holders

I have a question about the Redding competition shell holder set for. So I purchased the Redding type s bushing neck sizing die set for .308. The one that comes with the bushing neck sizer, body die, and micrometer seating die. Also, the Redding competition shell holders to bump the shoulder.
I Started practicing using the dies on some range brass I prepped starting with the .10 shell holder. My station number of my brass I used with the hornady headspace gauge was 1.624. I am trying to bump the shoulder back 2 thousandths and after using the .10 shell holder my number came out bigger 1.626. What exactly is going on here? I feel like the shoulder went the other way instead of of bumping back.
Is it normal and do I just keep working down until I get my 2 thou off the original number 1.624 or am I doing something wrong? I swear I followed the directions on the die and the shell holders that came with it. Sorry I was all over with this question but I feel like I’m making this a lot harder than it is.

-Vincent

Well I got down to the last shell holder and I got my 2 thou bump. It is just confusing the number going up the way it did with the first shell holder because I haven’t heard of the shoulder going the opposite way. I just don’t want to be working the brass too much. That is why I’m glad I’m using the range brass I got because i have some lapua virgin brass I am gonna load and want to make sure when I go to size and bump the shoulder on that brass that I am doing it right because that ****s expensive lol I’m still gonna load up the range brass and see how it shoots.

Varminterror said:

Setting your die to bump 2 thou on some random strangers’ range brass isn’t a valid path. You should be bumping based on YOUR brass from YOUR chamber, otherwise the dimensional change is meaningless.

The brass shoulder grew first because you were only sizing the body. Squishing the body skinnier without contacting the shoulder wasn’t actually full length sizing, and not yet pushing back the shoulder. Once you set the die deep enough to contact the shoulder, the body squished thinner AND the shoulder moved back.

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Ok sorry. Let me clarify. The “range brass” I used is my own brass i shot at the range that was factory loaded. I just call it range brass because I just brought it to plink at the range and it really wasn’t important to me vs the lapua brass that I will be doing my load development with.
What you are saying makes sense now. I’m just new to using these shell holders and am trying to get a grasp on working them down.