I need help, what's wrong with my chamber?

[BBob]

I have also never seen where the swelling is only happening on 1 side of the case and not the other.

Totally normal and an everyday occurrence with new brass unless I’ve been extremely unlucky for over 4 decades of reloading.

Some brass will bulge more than others. It can take several firings for it to even out.

 

[leachguy]

The 4 rifles I've reloaded for with Winchester or Nosler/Norma brass have done this. My one with Lapua brass did not. I wouldn't be worried if it were mine if I didn't notice any issues with case head sep.

 

[ElkPRC]

Totally normal and an everyday occurrence with new brass unless I’ve been extremely unlucky for over 4 decades of reloading.

Some brass will bulge more than others. It can take several firings for it to even out.

I find that very hard to believe as it has not been my experience or the Gunsmiths experience.

Again I want to emphasize that it’s not straight or all the way around. The brass is going to expand to the dimensions of the chamber and then spring back slightly. If it is not doing so uniformly than wouldn’t logic determine that something have to be crooked or off center?

I have never seen a rifle bulge or do anything other than a very fine line at the end of the chamber. This is very visible and can be felt on the inside and outside of the brass.

I’ve also heard people say the thickness of the brass is inconsistent and it could be a thin part of the brass….. but it’s the same on every single piece of brass. Which would be it extremely consistent. This has to point to a reason behind it.

 

[ElkPRC]

The 4 rifles I've reloaded for with Winchester or Nosler/Norma brass have done this. My one with Lapua brass did not. I wouldn't be worried if it were mine if I didn't notice any issues with case head sep.

The ridge can be felt on the inside of the case as well. This is what makes me worry about case head separation considering it’s factory ammo on first firing.

 

[huntnful]

The ridge can be felt on the inside of the case as well. This is what makes me worry about case head separation considering it’s factory ammo on first firing.

It would be on both the inside and outside. I’ve never shot anything but handloads in my 6.5 PRC AW chambers. I would try some Lapua brass handloads before over analyzing any further honestly. There’s nothing that can really be in the chamber that would cause it. It’s just a concentric tube that tapers from one end to the other, based off reamer dimensions. I know it wants to be thought of as more complicated than that, but it isn’t honestly.

I do think that your line appears to be more prominent than my own, but that’s also hard to tell from photos. Taking some photos all the way around the case would help others possibly figure it out also.