I sent a message through the brownells.com website to the attention of the Customer Service department describing the missing contents of the bag. I wasn't sure how to send this back: Did I have to package everything back up and send it to them, maybe get some sort of authorization? Surely I would have to talk to someone.
I shouldn't have worried. Almost immediately, I received a reply apologizing for my inconvenience, and letting me know they would make it right. Not two days later, sent priority overnight, I had a complete set of grips. The invoice asked the picker to make sure that the package was correct and all pieces were present.
Honestly, I'm not a big customer. I might shop at Brownells.com some five or six times a year, mostly small parts purchases. Didn't matter to them, they did the right thing immediately.
I don't know why this level of service surprised me, but it did.