For them, there was only one choice.
Here's a short video put together by the Military Times, which includes actual footage of the surgery where Dr. John Oh removed the live round with the help of volunteers and a member of the EOD (explosive ordinance disposal) team. Thanks to the brave men around him, Spc. Moss did survive that day and has since undergone six operations and is doing well at home in Gainesville, GA.
I think you'll find the video absolutely remarkable. (Warning ... some of the following footage is graphic)
Thanks to Military Times & to Suz