Weird sizing and seating issue

[Baron85]

I have been loading some lapua 6.5x47 brass that has 12 firings on them and the last couple times seating Bullets feel like they are hitting a wall then pushing through. Like there is a ring inside the neck it has to go through. It is just past the entrance that I feel it. Not all cases have this but let’s say about 1/2 of the 200 count lot I have does this. I just bought a pma neck expander to see if that helps and I can obviously feel this “ring” on the down and up strokes. The brass has been annealed after every firing since probably the 6th firing on my benchsource, resized with Redding types dies with no expander and .002 neck tension. What could be causing this and what would be the cure? Accuracy and ES/SD have gone down the drain.

 

[Baron85]

And to clarify I can not see a ring in the neck and am not able to measure a ring it’s just the best way I can describe it. I have also noticed my seating depths and shoulder bump have gotten progressively less consistent over the last few loadings.
I’m wondering if I am not properly annealing the brass and it is getting harder? I ordered some 750 Templaq for the necks to test. I have been using the primal rights method of go till the flame changes then back the time down about 1/2 a second

 

[Evintos]

It's a called a donut or case neck donut. Very common when sizing often without an expander. What causes it is material moving into the case neck/shoulder area during the sizing process (without an expander) and firing process. Using an expander will push the material "outwards" and drastically reduce or eliminate the donut. The options you have afterward using the expander is to neck turn if you want to maintain consistent neck thickness or just leave leave it be and eventually you'll end up trimming the material when the case length grows.

If you don't want to use an expander you can ream the inside of the neck with a trimmer or lathe which will remove the donut.

 

[Baron85]

So the brass is save able if I start using the expander each time and within a few firings should work itself out? Definitely don’t want to get into neck turning at this point.

 

[Evintos]

So the brass is save able if I start using the expander each time and within a few firings should work itself out? Definitely don’t want to get into neck turning at this point.

Yup, and depending on the expander mandrel (or ball) size, it might work itself out in 1 go. After that you can go back to neck sizing only but the donut will start to grow again. One way you can prevent the donut from growing too large without using it every single time is to use the expander every other firing or every couple of firings. Although for consistency, I would say it's better to use it every firing.

 

[Baron85]

Perfect. Thanks fir the help. I will plan on using the expanders every time and will also pick up expanders for my 308 and 223ai to help prevent this since I have used the same system with them but just haven’t fired them as much.