Of course, you have to sue first though.... I dismissed my most recent NICS lawsuit today, a short 54 days later after filing. My client was denied a purchase in January 2016. After appealing the denial, he was provided the commonly provided letter from NICS, in March 2016, that it was currently processing appeals from "June 2015." (I see on the website that it is now up to "August 2015").
After contacting me in late May 2017, my client decided to go forth with a lawsuit to vindicate his rights. I filed the suit on June 28, 2017 and service was perfected a short time later. On August 17, 2017, we were provided with a letter from NICS stating that my client was not a prohibited person and could thus purchase and own firearms.
So, if we count the days from the date of filing to the date of dismissal, we are looking at approximately 54 days. Not bad. Not good either though. Because until Congress fixes 18 USC 925A, the client is on the hook for paying the attorney to fix the government's errors. Back in December 2016, I assisted a congressman with some language that would "fix" this, but it has yet to be introduced. If not now, when?
This was my fifth NICS case, and so far, I have been successful in "winning" all five.