This is a very sorry subject that seem's to pop up on this forum every couple of months. The simple truth of the matter is that if you work on any firearm and then something goes wrong later on you could be sued for it. That include's installing aftermarket parts of any kind or altering any part of it. In this country if you walk out the door and scare the Niebuhr dog and the dog bites the mail man you could get drug into a lawsuit. Now this makes me wonder just how many of the participants on this forum have not altered one of their firearms at some point in time. I myself don't plan to sit around and loose sleep over it. I have been sued before.