As Link notes about the comments he submitted:
I downloaded the poorly planned 516 page PDF and immediately searched for a distinct portion of my email address. It was not found. I know I submitted an email to the BATF on this matter, and I also knew that I had received an acknowledgment from the ATF confirming receipt of my email.
I searched and found their receipt email which I was initially going to post, but as I dug deeper into the rabbit hole it became less relevant. Their receipt email was sent to me on 13 May 2011, which struck me as bizarre, since I knew I sent my response to their request for comment prior to attending the NRA Annual Meeting at the end of April 2011. I searched my sent items and found that I had sent them my thoughts on their "study" on 8 April 2011.
Read the whole report which includes a link to the ATF released comments. The link to the study is below.
Peace, Love, And Ammunition: BATFE Shoutgun "Study": I Smelled A Rat
UPDATE: According to the ATF label on this file at their website, these are only the responses received up through March 6th.