I am launching a build thread to document my fabrication of a 1911 frame using only the tools available to me in my garage. I am taking this on more as a mental challenge than the desire for a handgun. I found a wonderful set of prints for the 1911 created by Rio Benson, Benson Consulting, LLP, ©2010, and used them to create my 3D models in Solidworks. It is legal for me to do this if I build it on my own using only tools I own. I already have a legally registered pistol I will use for parts, and if I succeed I may just chop the fabricated frame up and destroy it. Building your own frame is a contract binding till beyond death--you can't sell it, you can loan it, you cant bequeath it to your kids, you literally have to take it to the grave with you when you die. And if you get stopped with it on your person, supposedly you have to prove you built it yourself according to all the rules stated here. Sounds like a lot trouble, but attempting the build will be a great challenge nonetheless.
Anyway, I own a table saw, drill press, 3D printer and a little home made CNC router that I use to make mandolins. I have found that if I take off only a little bit of material at a time, about .020", I can shave down a block of 6061 aluminum to most any shape. Oh about materials, since I will probably trash the thing when I am done, I don't want to spring for exotic material such as 7075 aluminum (I know its not that exotic, but I don't have any). I have some 6061 bar and some 01 tool steel in my scrap heap, so I am using that. I will make the frame from the 6061 and the rails from the tool steel. the rail inserts will be pinned and epoxied into place. You'll see. My design methods do not revolve around what is the easiest, or most producible, or even the what makes most sense. I design for what I got laying around the house.