Common? Yes, for European and Russian rifles. You should see how an HK-91 dings the cases. Does little to affect the reloadability of the case. Most of the dent will disappear when resized. The rest will iron out upon firing only to be replaced by new dents upon ejection. Don't worry about the dents.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball