Just finished the bolt now I need to double check the dimensions of the holes with some gauge pins at work and go over it again then I can make some prints.
This is AWESOME!
What kind of tolerances should I expect to be within when milling all the parts of the receiver?
There are guys who can center-punch and drill a hole to within .005". The damned drill bits always fail to cooperate with me, though.
The old bench-work method is to only lay out and drill one fastener hole. Use that to bolt the pieces together - you can use superglue to help keep them from slipping - and then lay out, drill, and tap the other holes. Use acetone to dissolve the superglue, then open up the holes on the top part so the screws will go through, countersink or counterbore as needed, done.
The other trick is, if you're trying to get a bunch of bolted-together bits to all line up neatly, is to leave a bit of extra stock on the edges. You can then mill, belt-sand, or spindle sand the stack so everything looks neat. Those reciprocating spindle sanders can do amazing jobs on internal curved surfaces.
Of course, if you're using CNC you don't have to worry about that sort of thing...
Probably an artefact of kpdf or something, but when I printed the drawings the numbers showed up fine, but not the lines on the dimensions.
It just occurred to me that, with a few modifications to your design, you could use sheet steel for the side pieces, a few machined bulkhead pieces, and rivets to hold it all together.
Perhaps I need to change my medication. The Voices are getting strange lately...