Here is 5D Tactical’s own video on using their Jig to machine out an AR 15 billet with a router.
Here isHere is a test firing of the home built lower receiver after installing the internal parts and when mated to an upper supplied by Stag Arms.
As you can see the home machined AR15 works perfectly. The cost of the aluminum billet was $80. The cost of a bag of mil spec parts was %60. Compare that to the cost of purchasing an AR15 lower built by someone else at your local gun store (usually upwards of $400. Note also, because you started with what is just a funny shaped block of aluminum no background check or waiting period was needed to buy the billet. They are also available in plastic should you wish to go that route.
Yes,, you will need a router. Many home work shops already have a router for wood work. You will also need a jig. That’s additional money, but usually less than $150 and you can use it over and over if you were so inclined (or sell the jig to someone else making their own AR).Once you have a jig you can photo copy it and make a new one any time you feel like it, using the photo copy as a template.