Handgaurd problem

[porry]

I have no idea what is causing this problem. I have a metal body on my gun, my handgaurds fit on when i had my broken plastic body perfectly. Now i have tried all the barrel furniture on the stock barrel, and my G&P one piece barrel and still have the same problem. When i mount the barrel and screw the chamberblock on, and try to put my handgaurds on, there is a space, about half a mm or 2 between the rear most part of the handgaurds, i cannot explain why, i have no clue. I am thinking that maybe if i get a G&P delta ring set my problem should be fixed. but yeah, any suggestions and or other people who have experienced this oddity?

Also, Does the TM RIS require the delta ring and the piece behind the front sight to mount? or does it attach to the barrel somehow?

I am getting quite mad, as a fix wouldnt be hard, i just want this thing to sit how it should, no rigged up fixes.