Need some help, I just can't remove the RRA National Match float tube, thre's a lock ring but it seems that RRA puts on a red locktite. I got two type on barrrel wrench and it won't fit on the fat tube and can't reach the barrel nut  Needs help.

tag for knowledge

As you figured it out, the three pieces are loctite together to keep them from loosening up.

First step is to remove the front sight block,

Then use a blow touch (only need to heat the parts to 600*, and you will smell a sweet smell when the bond is broken), break the loctite bond.  Back the locking retaining nut back two turns towards the receiver, then spin the front tube section off the barrel nut (the threaded section).  Then spin the lock ring forward or off if needed to get the barrel wrench to fit the barrel net.

When you reinstall, everything backwards, and use Blue loctite to bond the parts back together.  Also, when you go to lock the retaining ring back against the tube, it helps to have the upper vice with the bottom up.  This allows you see the index of the front swivel, and index it down the center line of the take down lugs (read you want to hold the tube indexed stationary with one wrench to back up the tube, and just spin/tighten up the retaining ring.

And regarding the length of the tube, you want the tube left long, and to the point that getting the hand guard is a real PITA (read need to use a tool on the delta ring). This keeps the hand guard from twisting as you sling up tight.

yeaaakkkksssss there's a small screw hiding under the FSB didn't notice because it was covered by the sling swivel a few hit and the barrel got dinged, cheers to RRA for hiding this thing. brilliant idea, you can't even loosen it without removing the float tube. Reminder to those who will......   Do not first remove the FSB, it's better to loosen the float tube then move it closer to the barrel nut 'till the small screw exposes under the sling swivel or where the bayo lug is located. loosen screw and take the pins out  before using the rubber mallet.

Thanks for the info