This is kind of a wierd one. I am thinking about using my existing frame of my sigma, fully disassembling it, and making an aluminum cast mold to replace the polymer. Has anyone here ever attemped to do this? Most if not all of the internal workings of the gun would use the existing parts and the gun would work the same as it does now.
The reason for the question is I think i would like some additional design features not available. I would like to have a modified trigger guard, standard rails, a different handle style and to just see if I would be able to. Any words of wisdom or thoughts?

Besides being very difficult and cost prohibited, you need a license to manufactur handgun frames. Now you can make slides with out anyone caring. Are you planning on using steel inserts like the polymer frame for the slide to run on?

it will not work, casting involves a lot of things, one being shrinkage, you would have to have a form slightly larger that what you wanted the finished frame to be. besides it would not be worth it, the aluminum will crack the polymer won't. just buy another gun.

I thought you only needed an FFL if you planned and selling the frame, not if it was for personal use. KInd of like something else. LOL

As far as shrinkage and the mold is concerned, When you make a mold there are some steps to follow. Such as coating the inside of the original with a material that will not stick to another and you have to do this about 3 times. 1st take the negitive impression. in this case I will be using a negitive, just not this one, fine tune, coat and take a positive. Repeat, repeat. Now you will have a negitive impression slightly larger than the original.
I did not plan on using steel inserts. The cooling rate between the steel and alum. is to great. I was going to just use a solid alum frame.

No license needed. You don't even need markings. If you sell it later, it would need a serial number & makers name stamped on the frame. I'm sure there is some ATF regulation concerning the amount of frames you make and sell and a licensing requirement.

Folks make simple MAC 10 frames frequently. It's just one piece of folded cut sheetmetal.

__________________
NRA Benefactor