I was just wonder, does a free float gas block exist? Has anyone heard of such a thing?
Seems to me it would be a pretty cool idea and could mount to the free floating hand guard, however I can't seem to find anything on it so I figure my answer is no.
On a 5.56 upper? The gas block has to deliver the gas to operate the bolt, so unless you're running something that doesn't use the Direct Impingement (ie 9mm, 22lr) then you'd be stuck with a single shot gun with a blow hole in the barrel
Now if you're talking about just running a low profile gas block, run longer FF hand guards over the gas block and mount a front sight on the rail.
I suppose what you are suggesting is possible, but I don't think there is ANY benefit in mounting your gas block to free float handguards.
At least I think that's what you were referring to in your first post.
Forgot to add, "free float" isn't really the proper term for this setup since the gas block has to touch the barrel to be functional.