I know I have to pop out the pins, but isn't that thing pressed on? I need to get it off so that I can use my free float tube and its new nut. Should I put it into a vise and smack it with a hammer?

I've heard the horror stories about this operation. So far, I have been lucky, I guess.   I needn't remind you to drive the pins out left to right. Brownells sells a tapered drive pin punch with a cup end made specially for this purpose. Highly recommended!. I always use a gunsmiths bench block under the sight. A deadblow hammer heavy enough for the job but light enough for you to swing comfortably is the ticket. If you live in an area that supports rust it wouldn't hurt to use a penetrant like Kroil and soak for a few hours prior to attempting removal. And - almost forgot - no, the sight base is not pressed on. You should be able to pop it right off with a brass or plastic hammer after you remove the pins!

Punch them out Left (NON EJECTION PORT SIDE) to right side.

It WON'T COME OUT THE OTHER WAY AROUND (I learned that that is the most important thing to remember.)

(the punch with concave end will help a lot if the pins are milspec rounded end pins) I've never used a concave punch though and while I have gotten the posts off sometimes they aren't pretty if the punch slips.

One of my bushy's needed to be heated with a torch before pins moved. And then it was kind of fused because of the bake on finish that BM uses after the posts go on.

[b]After pins come out a rubber mallet to the post will get it off it doesn't want to move[/b]

Thanks for the input. I am hoping that since this is a brand new barrel just out of the package that the pins will pop out easily. I was concerned that the sight was pressed on too and it looks tough to get a good hit on it cause the front handguard ring is in the way.

A coating of heavy grease over the barrel will help it slide off once you get it started and will reduce the chances of scratching the finish.

  Use the heat Luke.

   (It makes things expand, remember? :P)

Once you get the pins out it should be easy to remove the sight base.  I have never had any real trouble getting one off, except the one time when an after market gas block had been put on with locktite.  That was miserable and I had to use a tourch to heat up the thing.  A normal sight base will probably come off easily.  Watch-Six