Trying to understand what you mean, are you saying that when you back the outer receiver nut off to the alignment position, you can't get the inner barrel retainer nut tight enough? Or is that what you're trying to determine? I installed one of these on a build some time ago, and I had to back the receiver nut off a little bit to get correct alignment, but it didn't keep me from getting the correct torque spec on the barrel nut. (You can read the thread here: http://308ar.com/forum/dpms-lr-308-general-technical-discussion/installing-the-jp-vtac-fft-aka-'how-bibliophobia-can-make-your-life-exciting!'/msg2218/#msg2218) All I did was use a small rod to maintain alignment of the gas tube holes while I torqued the barrel nut.