How do you guys recommend cleaning the outside of the barrel that is hidden beneath a free floating rail system? Is there a preferred method for cleaning/oiling this that does not require removal of the rail system?
Non Chlorinated brake cleaner. just use it to spray down and it will dry on its own. If you get mud under it just wait till it dries and break it up with whatever fits in the holes.
I have a DD free float rail, but have not oiled under it yet, guessing you could use a spray or pump to spray it down, may take quite awhile for it to dry though.
Dilute some CLP with Odorless Mineral Spirits. Using a spray bottle, spray this mixture onto the barrel through the HGs. Follow up with compressed air to remove the excess.