OK last last comment, are you absolutely sure that that 'threaded part inside the HG ' isn't just stuck in there? Usually that is where makers stick their compatible barrel nuts. Do not think I have ever seen a HG with a threaded inner, but I'm usually only half right most of the time!
Ok this was it! You are right in this case so I think your average went up from half of the time
Thank you for pushing me in that direction. I thought it should have a separate nut to attach to the barrel nut, but it wouldn't budge originally. I didn't want to mar it up by using tools. After reading your comment, I went back in from the opposite side of the handguard and drove it out with a plastic coated shotgun cleaning rod. Had to pound it pretty hard, but it came out.
I was able to torque the now separated handguard nut to the barrel nut. However with the factory ruger barrel nut it still had the gap as shown in my previous picture. I replaced with the PVA nut, and now its completely flush.
It basically stays on there via compression nuts on the bottom, but its an extremely tight fit getting it on, so hopefully it should be stable.
I can now say this is a decent lower cost handguard option for the RPR. Not nearly as nice as the old Midwest Industries that they don't sell anymore, but I'm happy with it. Hopefully this will help anyone else who purchases this, as there are zero instructions with the unit, and no tech support to help at the company (at least with this product)
Thanks for all the responses and help! Picture: