IF you go to Kahr's web site at
http://www.kahr.com and download the generic manual you'll find this issue addressed on page 18.
Basically kahr says that dented cases are NORMAL, and the gun doesn't need service.
As above, the Kahr IS NOT a target shooter or plinker for reloaders.
It's not a 1911 which can be tuned to eliminate damage, but still be reliable.
It's a pure defense gun, and the state of ejected brass is a non-issue.
The only "test" for the Kahr is whether it reliably operates.
In short, nobody sane worries about what color their life vest is, what design is on the seat belt, how shiny the hard hat is, or what the brass ejected from the gun that just saved their life looks like.
My K9 tears the case rim up, AND dents the case mouth but is still 100% reliable.
If your Kahr is reliable.....Don't "fix" it. It's doing what it's supposed to do.