If I'm going to free float a 77 MK-II(and I have many times), I prefer to first bed the recoil lug, and tang. It's a lot better to do this first. After the bedding dries, like Coyote Hunter said, it's pretty easy to float the barrel.
If you don't bed first, Ruger 77's tend to just let the barrel keep sinking lower in the barrel channel till at times, you can go so deep you'll get into the sling swivel stud. Most times if you bed the action first, it's only a simple matter of sanding out the pressure point at the end of the forearm, and lightly widening the channel a few thousandths to achieve a very nice job. When I'm done with one, it's hard to tell that it's even floated untill you slip a few bills under the barrel, and slide them back to the action.
I'm not quite sure where all the stuff about sporter barrels shooting better with a pressure point comes from. Maybe the big magnums? All I know is that when it comes to the 77's, every one I've ever seen shot considerably better with a fully floated barrel. This is of course with a proper bedding job too. I have a 77 MK-II 223 that out of the box would consistantly put two shots very tight, and then procede to walk the next three high, and to the left every single time no matter what the load was. If I let 10 minutes or more pass between the shots, it'd group 50g Nosler Balistic Tips(5+ shots) at 3300 fps into 5/8" at 100 yards. After I bedded the action, and floated the barrel, I sat down, and put 20 shots into less than 3/4" at 100 yards as fast as I could shoot, and reload.