I've had the tapco stock sence they first realsed it, before I even bought my mini . I litterly had one of the first ones that came out. Before they even had the top hand guard , I just put a choate ventelated hand guard which helps keep it running cool and just looks mean. But the bottom removable hand railis what this tip/fix is for. Over the first year or two slidding the bottom rail on and off took a small tole on the fit of the bottom cover of the bottom rail, not much, but enough to anoy me and shake a little back and forth in my hands. So this is what I did, you need to purchase medical grade water proff adhesive tape, in a 10 yard roll, the case is red and white and looks like pipe thread tape. The tape is white and 1/2 " at the drug store. After you have that simply take your bottom rail off MAKE SURE YOU PULL YOUR SLING SWIVLE UP OUT OF THE WAY!!!. Now simply take a strip about 5 to 5 1/2", about 2 in Back away from the pointed top,inside on the botom put down 1 strip straight down the center. When you look at it upside down you should see a 1/2 in of the tape thrught the slits for the release tab. Now put 1 more layer, of the same tape, over the first. This will correct any shaking rattling or wobbling of the bottom for arm. Now the first time you have to put it on, you have to pull the release tab back and out, because the fit will be tight just slowly slied it on and off once or twice. This has remedy the problem on my rifel it has a nice hard firm grip now as opassed to shaking in my hand. Hope that helps. PLEASE PM ME IF IT DID !!!