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9/22/2017 12:11:25 AM
Posted: 8/27/2003 6:10:45 PM EDT
[Last Edit: 8/27/2003 7:22:49 PM EDT by cmjohnson]
This is mostly to test and ensure that my pics I just uploaded actually work.

This rifle is built on the zero percent forging that I milled out in my garage on an Enco milling machine.




Here's the other side. Some engraved data has been obscured for security reasons. Note the splotchy appearance in that one area near the mag release. This was due to a reweld that didn't anodize the same. (The reweld was necessary because a milling cutter dropped out of the collet and did damage there.)



Functionally, it's perfect. No jams, USGI mags drop free, and you have to apply just the right amount of slap to the bottom of a full 30 rounder to seat the mag catch when inserted on a closed bolt.

Accuracy out of this rifle is under 0.5 MOA based on my own test firings from sandbags with my best handloads at 100 yards.

It has a few minor cosmetic issues because I made a mistake or two that I had to have rewelded for rework, and the anodizing and dyeing of the aluminum went a little differently over the welded areas. But these are minor issues and the rifle is a fine machine, reliable, tight, and accurate.

CJ
Link Posted: 8/27/2003 6:44:52 PM EDT
Let's see the other side.
Link Posted: 8/27/2003 7:18:00 PM EDT
i don't know anything about machinng stuff but it looks pretty damn good to me. how many have you done?
Link Posted: 8/27/2003 7:19:39 PM EDT
Congratulations, that's a fine looking project for a 0%. I do have two serious questions. 1: As you look back on the whole project, was it worth it? Does the satisfaction of doing it yourself over-ride the time/labor/tools/setup involved? I'm thinking of doing this type of build myself, but I'm still unsure if I have the patience. 2: How did you machine the magwell? Broach? long end mill? file?
Link Posted: 8/27/2003 7:28:26 PM EDT
It was definitely worth it to do it. I enjoyed the experience, I love creating useful things, (I build jazz guitars from scratch for a living, and that's several hundred labor hours each!) and it's worth it to me to spend 30 bucks on the forging and some of my own time to make something that would cost me a bit more to buy already made, plus there's the benefit that this is not on anybody's books. No 4473 in the world has this on it. It's "invisible". That has some value to me, or at least, it COULD, someday...but I have no unlawful intent. The mag well was milled out, but first I used fresh, sharp 1/8th inch drills to drill the corners out (8 points) and then I just milled between them with several sizes of milling cutters. A chore, yes, but certainly manageable. I'll snap a few shots of the very simple fixtures I made from scraps which held the receiver in place while I performed the various operations, and show how the receiver was oriented by putting my scrapper receiver (I had to make two to get one good one) in the fixtures on the mill table. CJ
Link Posted: 8/28/2003 4:09:58 AM EDT
Well I`m sorry but I find it pretty difficult to beleive your reciever was machined from bar stock aluminum.
Link Posted: 8/28/2003 4:25:21 AM EDT
[Last Edit: 8/28/2003 4:27:32 AM EDT by otto_esq]
Paulx -- I think he started with a zero% forging which looks like this [img]http://www.tanneryshop.com/files/forging.jpg[/img] Instead of bar stock. I agree it would be quite a trick to get something that looks like that from bar stock in a garage (or anywhere for that matter) Home machinists can start from 80% forgings (meaning that 80% of the machining is already finished before sale to the public as a "non-firearm" under federal law, but few of those look as good as this one started from essentially an aluminum paperweight. Cheers, Otto
Link Posted: 8/28/2003 5:25:52 AM EDT
Outstanding CMJ! I have one 80% NOC casting finished and one about to be finished. Then anodizing and assembly. Where did you get the forgings from? I want to do a couple 0% next. Did you anodized your lower?
Link Posted: 8/28/2003 5:37:15 AM EDT
Great looking AR. I wish I had that kind of talent to do work like that.
Link Posted: 8/28/2003 5:50:07 AM EDT
No talent is required. Just some basic machinist's skills, a milling machine, a vise, a sparse handful of end mills, a few scraps of aluminum to make simple fixtures with, and the lower receiver blueprint that's so readily available...and the basic blueprint reading skills necessary to interpret it. I went the extra mile and actually bought the buffer tube tap from Brownell's, as well, but if you know a gunsmith who has one, you might not have to buy your own. I also discovered how easy it is to anodize and dye things in your own garage. That's my anodize and dye job. Tools required: A 12 volt power supply (a decent car battery charger is sufficient), a plastic bucket, a box of battery acid (sulfuric), an aluminum plate, and an aluminum rod threaded to the right size to thread into the pistol grip screw hole. Black RIT dye, and a big box of baking soda, too. Total cost (excluding the battery charger) is maybe 20 bucks. And yes, this was from a raw FORGING, not bar stock, as Otto showed. CJ
Link Posted: 8/28/2003 9:43:13 AM EDT
Good looking lower. I have done 2 myself and I am currently working on another. I have one question. How did you engrave the SAFE FIRE on the lower. I have been thinking about punches but I am concerned abou screwing it up.
Link Posted: 8/28/2003 12:50:38 PM EDT
[Last Edit: 8/28/2003 12:53:25 PM EDT by RogueAssassin]
cmjohnson... I have to side with paulx on this one... I can not believe that you milled this receiver you posted the picture of. Now don't get me wrong I don't doubt you skills as a machinist, [b][red]BUT...[/red][/b] [b]Why did you put a serial number (65020xxxx)???[/b] If I had milled my own it would have my initials followed by "000001" or 2,3,4, etc... May be this is you SSN??? [b]Also.. Why did you place "CAL. 5.56 NATO" on it??? This just looks a little too generic. If you did mill this then forgive me of doubting you... I would have "jazzed" up the engraving on the side so there wouldn't be any doubts as to who make it.
Link Posted: 8/28/2003 2:58:36 PM EDT
WONDERFUL! I don't care if it takes 250 hours- some day I hope to do what you have done. The home anodyzing is especially interesting. Did you find any resources that were particularly helpful in setting up? Pete
Link Posted: 8/28/2003 5:16:30 PM EDT
[Last Edit: 8/28/2003 5:17:51 PM EDT by philsAR]
That's freakin great man! 90 % complete on first one right now. I'm working on this with the help of a friend, both learning milling techniques and reading blueprints as we go. So far, a couple of mistakes but I think the first one will actually function. Used the same technique for mag well. That took a long time. Sounds like your lower works great! It may not be beautiful but it is funtional and best of all, no paperwork. [beer]
Link Posted: 8/28/2003 6:47:34 PM EDT
Originally Posted By RogueAssassin: cmjohnson... I have to side with paulx on this one... I can not believe that you milled this receiver you posted the picture of. Now don't get me wrong I don't doubt you skills as a machinist, [b][red]BUT...[/red][/b] [b]Why did you put a serial number (65020xxxx)???[/b] If I had milled my own it would have my initials followed by "000001" or 2,3,4, etc... May be this is you SSN??? [b]Also.. Why did you place "CAL. 5.56 NATO" on it??? This just looks a little too generic. If you did mill this then forgive me of doubting you... I would have "jazzed" up the engraving on the side so there wouldn't be any doubts as to who make it.
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I take your skepticism as the highest form of compliment, and I'm glad to know that there are still a few people alive who don't believe everything they're told. However, no BS, I did in fact mill this out from a raw forging. An Alcoa forging from die no. 25 on it, to be exact. The engraving was all done via a CNC mill at the local college's machine tools shop, which is a program that I took some years ago and I've kept in touch with them. They'll do just about anything for you if you ask nicely and pay for the materials, as student projects. But that shop ONLY did the CNC lettering, and NOTHING else on this. The rest is my work. The serial number is in fact my SSN. You will note that the SAFE marking is misplaced. Oh well. It still works. Part of what is airbrushed out is C.M. JOHNSON. You can see the first letters. I marked it this way because, if it should by some horrible chance ever get stolen, the first time some cop finds it, unless those marks are removed (and they're pretty deeply engraved), it'll find its way back to me if at all possible. As I have absolutely zero intention of committing any crimes, I'm quite comfortable with this. If this were a factory job, they wouldn't have allowed it to be sold with the two obvious cosmetic flaws on the mag well face due to the rewelding before finishing. This one took about 40 hours of actual workign time, which I define as the time I spent actually working on it in the garage where the mill is. I probably spent more time fidgeting with the setups and triple checking my intended cuts than I actually spent with the machine even turned on, and I STILL made enough mistakes that I had to have it welded up no less than three times. (The third was the buffer tube ring, I'd totally blown the hole position, but the second time it came out perfectly aligned, and I do mean perfect. I couldn't measure the bore as being offset by even a single thousandths of an inch. I cut it with a boring bar (I didn't have a drill of the right size) with a specially ground HSS tooth that I ground myself specifically for this one operation. It left a mirror finish in the bore that was so pretty it was almost a shame to ruin it with the tap, but ya gotta do what ya gotta do! It was a lot of work and was very rewarding. It'd be interesting to do it again with a better selection of tools and some properly engineered fixtures. I flat out had to guess at some of the features in this thing. The hole for the buffer stop, for example. I estimated that one by installing a buffer tube and then marking where it stopped, and measuring the stop itself, because I couldn't quite figure out how to reference that hole to the rest of the measurements. CJ
Link Posted: 8/28/2003 7:33:10 PM EDT
Dude... Congratulations on your first mill... Next time, you need to trick-out the engravings on the side... especially your name. "CM Johnson" in standard font is okay, but try to come up with a logo of some sort for your next mill job. Something simular to DPMS or Bushmaster (for lack of better examples) you can always add "Builder: CM Johnson" under the Serial(SSN). Again, Just want to say Congrates.
Link Posted: 8/29/2003 4:58:38 AM EDT
Originally Posted By cmjohnson: I also discovered how easy it is to anodize and dye things in your own garage. That's my anodize and dye job. Tools required: A 12 volt power supply (a decent car battery charger is sufficient), a plastic bucket, a box of battery acid (sulfuric), an aluminum plate, and an aluminum rod threaded to the right size to thread into the pistol grip screw hole. Black RIT dye, and a big box of baking soda, too. Total cost (excluding the battery charger) is maybe 20 bucks.
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Can you provide more info or post a link on anodizing?
Link Posted: 8/29/2003 5:36:57 AM EDT
Google it. "Anodizing at home", etc. That's where I found the information I needed, and it's been so long since I found the information on the internet that I have no idea exactly what site I used. A quick search showed plenty of hits. Should be no trouble to find it. CJ
Link Posted: 8/30/2003 3:43:53 AM EDT
CJ, You did a fine job on that lower! I have found that the key is good fixturing. I would like to see those photos of your fixture plates and will be happy to post mine. I am currently working on a long overdue book on how to cut the lower from the forging. You are right about the anodizing. It is so easy it is silly not to do it yourself. Here is where I got my annodizing info: [url]http://www.focuser.com/atm/anodize/anodize99.html[/url] I get my forgings from DSA, $25 or $20 for quantity [url]http://www.dsarms.com/[/url] What held up the book is the photos. Seems every time we ran a lower through we forgot to take come critical shot or another and needed to wait until the next lower was in the machine. Now I am modeling the entire operation, all 11 setups, in Solidworks and the book will be illustrated with line drawings. I hope to have it finished this year. [img]http://www.ray-vin.com/firstsetup.jpg[/img]
Link Posted: 8/30/2003 5:24:27 AM EDT
Hey Thulsa Doom, Nice work. I'm very impressed. Cheers, H
Link Posted: 8/30/2003 5:55:57 AM EDT
That's really cool. Congratulations, you will I'm sure have a great sense of pride every time that weapon goes boom/sproing. [:D]
Link Posted: 8/30/2003 6:33:05 AM EDT
Totally cool. I'm undertaking an 80% project right now, but I think that the 0% is next.
Link Posted: 8/30/2003 7:47:06 AM EDT
I've done a few and my biggest problem has been getting the buffer tube hole correct... don't know why since I always believe its going in at the correct position. I've taken to laying down blue on the rear end and using the mill to mark a square box scribe on the 1.125 dimension. Then I go in with the boring bar and carefully take the hole to 1.125 so that it fits exactly in the box. I think the problem for me has been that I am using a mini mill and the boring head setup is a bit much for it.
Link Posted: 8/30/2003 8:00:26 AM EDT
nice work, I'll hopefully get around to having money again and thus the tools to do some myself [:)] [beer]
Link Posted: 8/30/2003 12:39:40 PM EDT
Originally Posted By NevadaARshooter: I've done a few and my biggest problem has been getting the buffer tube hole correct...
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[url]http://www.concealcarry.org/ar15/bs-reaming.htm[/url] Try that method next time. [:)]
Link Posted: 8/30/2003 3:14:30 PM EDT
Originally Posted By ProfessorEvil: ... [url]http://www.concealcarry.org/ar15/bs-reaming.htm[/url] Try that method next time. [:)]
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hey that's pretty cool, one of those "duh, why didn't I think of that" kinda things [:)]
Link Posted: 9/5/2003 9:08:40 AM EDT
Nice Job I am working one my first one too but the learning curve is starting t flatten out.I have been doing it after work as I don't have a mill at home yet but I will....one day anyway.
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