Hi, first post here. Thought this may help some folks save some money and improve their RPR. I acquired a RPR Gen II in 6.5CM a couple days ago and noticed immediately the handguard had no rigidity, just a light tap with my hand would change the position relative to the bore. After searching online the only solutions I found were to live with it or replace the handguard with an aftermarket model. The problem is the excessive clearance between handguard nut and handguard. In may case this was approximately .010". My idea is to shim the barrel nut to reduce the clearance. Get some brass shim stock in the appropriate thickness. You can purchase shim stock many places online and it's fairly inexpensive. You could probably use multiple layers of aluminum foil but I suspect it would be a pain. The thickness in my case was .004". I don't know if this is consistent among RPRs, so you may need to try .003" or .005". Cut a piece about 1 1/2" x 5 1/8". It can easily be cut with scissors. It is ok to be slightly smaller, but shouldn't be any larger as you'll run into interference issues. Wrap this tightly around the barrel nut and hold it temporarily with a piece of tape across the ends. I positioned the ends of the brass at the 6 o'clock but should work at any position. Carefully slide the handguard over the brass. It should be snug and require jiggling of the handguard to install. If it's too tight/loose, try thinner/thicker brass. Once it fits snugly, mark the mounting screw locations. I simply used a pen to draw the inside of the holes. Carefully remove the handguard and shim. Cut out the shim material around the marked hole locations. Give yourself some clearance, 1/8" or so, to make positioning the shim easier. I cut mine with a 1/4" wide wood chisel and a mallet on scrap melamine. If you have one, a hole punch would be easier. Lightly tap around the edges of the holes with a hammer on a piece of metal to flatten out any raised edges and burrs. Position the shim on the barrel nut as before and reinstall the handguard. It may take some fiddling to line up the holes but it's not difficult. Install and tighten the mounting screws and enjoy your now rigid handguard. This took me about 15 minutes and resulted in a handguard at least as rigid as my Gen I RPR. DISCLAIMER: Modifying a firearm inappropriately may create a dangerous situation or void your warranty. Do so at your own risk.