The Delta ring does move as much as the hand guards, but when the hand guards move the Delta ring does not. I have noticed two small notches at the rear of the hand guard inside the "ring that slips into the barrel nut. (Check Fig. 1 & Fig. 2 Below) They are worn and the plastic has been eaten out, I don't know if this is the cause or it was due to the constant rotating back and forth. I have always noticed a small play but now it really bothers me when trying to aim. On this rifle I only use the A2 Iron sights, and even then it erks me to death.
On these notches is were I will place the silicone rtv ALAN308 advised and instructed, but wouldn't this were after time? What about new Hand guards? If I do go the New Hand Guards rout I'd like something solid that has no play in it, but I don't know of any manufactures that have them (solid triangle cap, and mid length). I have noticed on my Bushmaster carbine, the Hand Guards
DO NOT move at all, but on my LMT the M4 Hand Guards have quite a bit of play in them as well but nothing on the Armalite Middy level. The Lmt has a round cap that does not move, and the Armalite has the triangle cap (see Fig.3) and it does have just as much play in it as well.
Fig.1Fig.2Fig.3