I have never noticed this before and I've towed trailers everywhere with different vehicles. When I slide the ball mount into the receiver on my truck, I push it in, put the pin through it, and slide the pin through and put the clip on. Earlier I slid it in like normal and for whatever reason pushed it as far back as it could go. In doing so I kind of measured half-heartedly how far I had to pull it back out of the receiver to line the pin up--a good 5" give or take, which is not quite half the length of the ball mount. Why does the ball mount not slide most of the way back? Sure seems like it'd eliminate some rattling? I have an extended ball mount that is longer than usual (have to use it for one of the boats) and I could slide it all the way back, mark a new hole and drill it out. Is there any reason that wouldn't be a good idea other than having to drill 2 new 5/8" holes?