Senators Cornyn, Sessions, and Cochran have clarified their support for the Second Amendment.
Sen Risch of Idaho put out a strong pro-2A statement on his website but the statement is currently MIA and only available through Google cache.
All of these show the importance of contacting your Senator even if you think you know how they stand on the issue.
Meanwhile, several gun control Senators (Warner, Udall, Franken and Hagan) have shown signs they are getting concerned about 2014 and are wobbly. Keep pouring it on.