Take a proper rod and knock the round out.
Do not let Sig off the hook. I am a huge Sig fan but a broken gun right out of the box is unacceptable.
Send it back give them one more chance to make it right. If they cannot do that then ask for a check directly from Sig.
"Its a tool box... I don't care you put the tools in for the job that's all..." Sam from Ronin
The United States is a nation of laws: badly written and randomly enforced. -Frank Zappa
Without deviation from the norm, progress is not possible.-Frank Zappa