Just finished assembling the lower reciever... excellent way to learn the hard way about parts and their function. Interesting tidbits: 1. The exploded parts diagram is almost pointless. Refered to ARforum.com for a real photo. 2. There are videos online to explain how to put one of these together, in fact the above forum has some links and I recently downloaded one to furture reference. (PM for link) 3. Until I figured out how to use a small punch to help in installing the magazine release.... man I felt like a retard. 4. Use masking tape! Lots. Cover the end of pliers. I marred up the bolt release tabs after my pliers slipped while putting in the bolt release pin. Maybe some touchup pain or some old blueing solution will fix that up. 5. The smallest of springs, when compressed will have enough energy to put out eyes and fly across the house. Use caution and have a spotter. 6. Use a white sheet on top of the table top to make sure the small parts don't roll off and so you can easily see them. 7. Remember to slightly oil some of the parts prior to assembly. I forgot this wonderful step and instead 'touched up' the parts with a q-tip after installation. 8. The video makes it look like a 10 minute deal after you re-invented the wheel and finally assembled everything.