One learns the ins and outs of them. I have built dozens and owned 6 at one time. I also have what is considered the lightest one ever built. All aluminum 5.8 lbs and shoots the 7.62X25 round. I have my metric gun that I love. The best comprise is a DSA aluminum lower, type 1 upper and 18" barrel with the right furniture is a good setup that is a few lbs lighter and comfortable for most. Click image for larger version.  Name: toy3_zps8sronl3m.JPG  Views: 15  Size: 46.1 KB  ID: 76139