No, just one of the most well known.
I said democrats ARE always anti-gun.
You are wrong. Bacus, Tester, Begich, Udall, Bennett, Bayh, Landrieu, Burr, Hagen to name a few.
http://www.senate.gov/legislative/LIS/roll_call_lists/roll_call_vote_cfm.cfm?congress=111&session=1&vote=00072
Burr is a republican, but perhaps you meant someone else. When push comes to shove, unless they’re up for re-election, they will vote with the left for gun control or an assault weapons ban. Or they’ll be sneaky and vote to allow cloture, then vote against the bill when they know it has the votes for passage. But there aren’t as many moderate republicans who can give the democrats cover anymore.