Finally got around to putting my AR together. I bought a complete kit, minus the stripped lower. When I went to put in the LPK last night, I looked and looked and couldn't find my punch set. So in an attempt to get it done anyway, I grabbed my spring loaded center punch. What an awesome idea for setting the roll pins. It's pointed, so it self-centers in the roll pin. A few punches from it and the springs were set. So much easier than using a hammer and a punch set. It's just a cheap one like this from Harbor Freight. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=621 Short story: If you're assembling an AR lower, use this.