Are these particularly hard to do correctly? I'm fairly OK with common machine tools and given a good jig like I see online, I think I could turn out a passible product... what say you?

The 80% AR lowers have jigs that let them be finished on a standard drill press.



80% 1911 frames are a different beast entirely, as you will need a mill to cut the frame rails, barrel seat, and a couple pin holes to far greater precision than an AR's lower needs to be drilled out. This also precludes fitting the frame, which requires specialized frame rail fitting bars.

Yes they are hard to do correctly.

It also would not be profitable as a business model to "tool up" for effective production of finished frames and receivers from 80% when, with just a bit more tooling, you could produce finished items from raw forgings or castings. 80% products are sold at really a high price point for what they are (level of completion).

What about building a 1911 from an unmachined casting?

Any links to websites or youtube videos that show what is involved?

I've done an 80% AR-15 lower and an 80% .308 AR lower, and the prices on the 80% 1911 frames have (so far) kept me from ordering one.

10/22's are popular too.  All are very doable with the correct machines and patience.  Given enough will power and patience, the tooling can be much less ideal and still produce quality.

I've done a couple of 80% lowers now.  slow and careful = fine end result.   I used Anderson 80% lowers and an Easy Jig and had no real problems. Just take your time.  

But the 80% lowers aren't much less than a finished lower so the biggest draw is just the fun of making one.  

Check out 1911builders.com for some kit ideas.   I'd love to build a 1911 from an 80% but the costs to build a complete 1911 but I have no real use for a low cap pistol in a caliber I don't use.  :)  There's a fairly cool tool to cut the frame for a 1911 that precludes the need for a milling device.

Duped

I've done a 80% AR10 from Polymer80. I did it with only a dremel, a few carbide end mills, and a router jig. I wouldn't do it again, takes forever to do and the cuts are rough. However it works and plastic is much easier to machine than aluminum. Lowers aren't high stress part so being made from plastic did not affect its function one bit (it worked so well it's boringly reliable).

I'm getting a Grizzly G0758 mill though... not really doing it just to do lowers but I also build guitars...

Link to 80% 10/22?

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There's quite a few available, here's a couple.   Razor , Tactical Machining, Iron Hammer

Take your time and have a good set of blueprints.  They're not hard to do, just be sure to pay attention to what you're doing.

I would not do one using a jig.  I've had a few friends that tried it with different jigs and then brought them to me to see if I could unscrew them.  In the end all of them wound up in the garbage as unsalvageable.  The jigs that I've been shown were all off in one way or another.  One had a buffer tube hole that was obviously off center just by looking at it.  If you don't own or have access to a milling machine then don't try it.

I rather do the ones where the fire control needs to be milled, rather than try to do the buffer tube. The buffer tube requires expensive tap and reamer, and too easy to mess up.

Drilling the hole is easy, it can even be 1/32" off and the firearm will function fine. Fire control pocket can be milled with a drill press, router, or dremel with end mills. The buffer tube hole is hard to do even with a milling machine.

Do the buffer tube first on a lathe.  Ta Dah.

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Assuming I have a mill...what else do I need to finish a 1911 80%?  What sort of clamp(s) or vise, and what size end mills?

I have a mill, I just have no idea what I'm doing.

I believe the slide rail uses 3/32" end mills. A lot of people seems to like using keyway cutter but I tried it once, never again. Using the keyway cutter basically requires you to clamp it on the mill standing up. The setup introduces a lot of flex as well as destroying the keyway cutter at the same time, leading to a rail that was too small. Instead I just clamped the frame to the mill table flat, and used the end mill to mill the rail, problem solved (to help with the setup use a machinist square to place a 1-2-3 block to the table, and just butt the frame against the 1-2-3 block)

The other part, I am not sure because I had the older frame that only needed the slide rail done.

As for the buffer tube hole I thought of a lathe. I don't have one but I wonder what size lathe do I need to do this? I've been trying to find out the dimension of a lower but not even the blueprint gave that information. It would also be useful for the barrel hole for the 80% 10-22 as well...

I'd want at least 18" center to center.  The receiver and its fixture will eat up the first 10" and then you need room to work.

The idea is to drill/tap the receiver in am area that's later milled out, like the fire control pocket, and the bolt on a piece of round bar of sufficient size such that when the two mate the buffer tube's centerline will be coaxial with the spindle.

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sounds like a benchtop lathe won't do. Like I said buffer tube hole is complicated to say the least. I'm wondering if Grizzly G4000 will work, however its weight does present a problem... (I live on the 3rd floor with no elevator)

Tactical Machining sells 80% AR lowers for 29 dollars each if you buy 3 of them. That price makes it almost pointless to buy a 0% forging (except if you just want to do it just because)

That's why I did it.  

Here's a pic of me tapping the buffer tube hole.  Machine is a 9x42 Bridgeport with the quill fully retracted and the table on the bottom travel stop.  Yes, I could have better optimized my setup, but you still need pretty good headroom to get it done.  



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doing it on a mill still requires the expensive reamer and tap (and honestly you don't need a mill for this, you could use a drill press)... looks like a lathe is a better setup for this (tapping and boring bars are pretty standard setup in a lathe)

I'm just wondering if a Grizzly G4000 is big enough for the job.

Yup, I bet it will do it.  You'll need sharp tools and buckets of patience.  



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