For most rifle enthusiasts today, building a rifle from scratch can simply be too time consuming. This is why many shooters prefer to purchase complete uppers and lowers and then simply assemble the parts from there. This way, you can replace any specific components that you want to while still having a working rifle in relatively short order. For a solid foundation, the PWS MK2 AR-10 Complete Lower Receiver is an excellent place to start.
Made using 7075-T6 Al forging and featuring a hardcoat anodizing finish, this lower was made to put up with the stresses of regular use in the field. It weighs a light 2 lbs. and 8 ounces, which is pretty impressive for a lower meant to take .308 ammunition. It includes everything you need in a lower, such as the PWS Enhanced Buffer Tube, stock, and grips. This lower is made with all MilSpec components, which will ensure its compatibility with any standard upper.
When you are looking to build yourself a rifle and want a solid foundation to start with, this complete lower is the perfect option to consider.