I've seen that occasionally in stock 450b cases as well. Not to the point where the case will not chamber, but visible with the light at just the right angle. It's not your dies. It poor QC when the cases were made and you got some with thicker walls. There is also the possibility of bullets being out of spec, but I've never seen them err of the side of too fat. I have seen a run or two where they were a little undersized as measured with a quality micrometer. Say .448 or .449 as opposed to .451. Still have the remainder of a box of C.O.P. bullets that were that way.
Here's a worse case of what happens when you cut down .284 Win cases and try to use them as 450b cases.
- DSC01478.JPG (59.19 KiB) Viewed 11923 times
Also, notice the bulge is asymmetrical. Again Poor QC.
This one was more common in its symmetry.
- DSC01479.JPG (59.21 KiB) Viewed 11923 times
Some of them would not chamber and had to be pulled down. This should not be happening with stock 450b brass. The wall is thinner in them. As Al said, as long as the chamber okay, you're good to go, but ask why. Mic a couple of your bullets. Unless you have a specialized case wall mic it'll be hard to quantify them.
Hoot
Hoot