If you are not going to machine the hole larger the stock hole from ( KNS) is .154 the next over size is .001 larger. measure your hole and go from there.
Good luck with that. When you get it have some one with a accurate 0-1 outside mic check the part.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: GMR</div><div class="ubbcode-body">is there any reason for adding this item if there is nothing currently wrong? </div></div>
I have had my pins come lose before on a new rifle so I run these on every single one I own. Pin can come lose and you are out of the game.
Watch out for the bolt hold open screw, that little bugger came out on me three times no matter how much loctite or force I put on it and mine is now somewhere between Elko and Reno. Thankfully it's not necessary for function.
almost sounds like the hole wasnt threaded or the threads are stripped if it keeps backing out. bummer spot to have an issue. i like it over the roll pin on an ar15 though