SmallCaliberCentral

I was going through some cases and measuring the case neck thickness and then started measuring the case neck runout and got a question befor I go any farther Do you resize before or after checking runout or both?? my once fired hornaday cases measure .011 through .014 in case neck thickness but no one case has a diffferance of more than .001 in thickness (.011 to.012 or .013 to .014) but when I went to check runout first case had .008 second had .007 and the third had .010 that is when I stopped and came back here to ask my question before going any further I am using a RCBS case master gauging tool I bought last night. I also bought a tumbler Dillon CV-500 and Turbo Bright brass polish by Lyman how do you get the polish to blend into the media (walnut was all they had) mine just kinda clumped all together in little balls and some stuck to the bottom of the tumbler Thanks for all and any replies Ulen MN

Ulen - run your tumbler for 30 minutes or so without brass. Actually, and I am NOT kidding, if you have a couple small rocks to add to the mix, this will aid in dispersing the cleaner into the media. Of course, remove rocks when done.

You can check the case neck runout before and after. But, if your wall thickness already varies, it is a moot point. Look at the case neck, just about every rifle slightly (or heavily) flattens once side of the neck, because the case extractor is tipping the case towards the ejection port when you are pulling the bolt back. So, you already have a flat tire that you are trying to measure for roundness.

Check the case neck runout after you size.

Check bullet runout of a loaded round too.