I was at a car swap meet this weekend and one vendor had 2 0% lowers for sale for $30 each. Got me to thinking. I realize it would be a lot of work, but if a person had access to a good mill how hard is it really to finish a 0% lower.

www.dsarms.com/item-detail.cfm?ID=1001&storeid=1&image=arforgings.gif

As for milling one, you just clamp the piece down, closed the lid, and hit the start button on the CNC machine.

Quoted: 0%? Do you mean a forging?

Yes.

They looked like they were straight out of the mold.

How can I tell the difference between a forged and cast lower?

I've got some lower forgings that I'm looking forward to attending to with a mill when I get it.

I have built two lowers using 0% forgings, three if you count the one I messed up.  It does take a lot of time on the mill, both in milling and locating the holes and slots in the proper spot.  I think a DRO would help a lot but I make do with the dials for now.  The hardest part is the mag well.  I usually take a large part of that out with a 3/4" drill or mill, then clean up the corners with a extra long mill of the appropriate diameter to get the corner radius correct or at least very close.  The extra long length and small diameter requires very light cuts.  By measuring the parts you can adjust the dimensions of some of the holes and slots for a tighter fit than you would get  just following the plans.  Maybe that just means that not all parts kits are the same.  I purchased my forged lowers from Dlask Arms Corp..  I believe they are $20 each plus shipping if you buy two or more, but I haven't checked in a while.

Ray-vin had a web site that tells you how to machine them on a mill.  Some of the best techincal writing I have ever seen.  I have machined several.  He uses a DRO.  I do not have one and they are not necessary.

If you have no machining experience they are tough.  Count on screwing up a couple.

It does require time to think to do it right.  If you can find Ray-vin's pages I would read them VERY carefully.  He shows the way, with lavish photos and illustrations.  The last word on the matter.

Ray-vin's tech pages Here

Well it is difficult and it isn't.  First you need the right tools... about any mill will do as long as you have the right tooling.  The only thing different between mills is the speed at which you can cut.  Something like a hass will allow you to cut the lower in an hour or two.  A mid size mill... about 8.

CNC and manual's will both work well.  Granted a CNC is nice if you are doing the same thing over and over.  For a manual mill, you'll definately want a DRO on it.  Counting turns just won't be suitable.

Ray-vin has a good step by step guide.  Roderus is ok, but he could be using more effecient tools for the job.

Quoted: As for milling one, you just clamp the piece down, closed the lid, and hit the start button on the CNC machine.

I seriously hope that was a joke.  Considering there is over 50 different things that have to be done with a lower.  There are over 30 tool changes that take place.  The lower/fixture/vise is adjusted 13 times.

But with some of the best machines out there, you'll still have to rotate/flip the lower at least 4 times.  Top/Bottom/Rear/Front.