I want to install a Jard 3# trigger assembly in my Colt AR15 Match .223. I understand that it is neccessay to clearance the sear block. What is the initial function of the sear block that does appear in most Colts? What is the risk? I read it can be done with a dremmel. Can you tell me if Im getting into something best left alone? What purpose does this block serve. It is held in place with a drift pin and what if it didnt exist (removed)?