New collector, need advice please

[browningautorifle]

Where exactly and what exactly with would you shim the top handguard? What would you use to clean the bore?

It depends on what the movement is, I had a piece of rubber tube in a handguard in an M1 rifle once. Small and just enough to stop movement. Hide it inside the metal at the end. Use good, new brushes and oil and it will come clean if it's going to. Shoot it a bit first and clean after to loosen anything up.