Retro Re-Profile by Hand

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[ARCHIVED THREAD] - Retro Re-Profile by Hand

Posted: 4/19/2020 7:05:11 PM EDT

I'ts been several years since I have done a lower receiver re-profile by hand, so I figured why not try and do one again.
This used to be the way many of us had to do our retro-rifles, and I thought some of you may get a kick out of seeing this process.

Those that have machine tools and the know-how to use them turn out some beautiful lowers, that's not what this is. This is an example of what you can do with a Dremel, some sandpaper, a few files and a little bit of patience.

Our subject today is a very common Anderson A2 profile lower:

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And here is a pic of the tools we will be using:

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Posted: 4/19/2020 7:08:25 PM EDT

[#1]

I started off with the sanding drum on the dremel tool, the intent was to remove the reinforced area around the rear buffer extension:

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Posted: 4/19/2020 7:12:40 PM EDT

[#2]

I then used the cone shaped angle cutter to start making the indented shape where the curve of the buffer extension meets the lower. I started off drawing a line where the crease should be, then carefully running the bit back and forth.

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I used some sandpaper to clean things up.

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Posted: 4/19/2020 7:15:02 PM EDT

[#3]

I then used some flat black spray paint to apply a guide coat to see how things were coming along:

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This will need a bit more work with some 100 grit sandpaper, but we can get to that later.

Posted: 4/19/2020 7:18:41 PM EDT

[#4]

Now it's time to do the other side. Pretty much the same process as before, but now we have to watch out for the detent reinforcement.

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Posted: 4/19/2020 7:21:21 PM EDT

[#5]

And again some 100 grit sandpaper to clean things up.

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If you fold the sandpaper at different angles you can get it to do some pretty cool stuff. Also, wrapping the paper around a file or a punch helps in some spots.

Posted: 4/19/2020 7:25:51 PM EDT

[#6]

Now we will do the front lugs. I started with a round file to get the inner radius:

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Then a flat file:

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And once again some sandpaper:

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Posted: 4/19/2020 7:27:18 PM EDT

[#7]

Nice tutorial.

Posted: 4/19/2020 7:32:01 PM EDT

[#8]

I then spent quite some time with sandpaper, smoothing out everything, and doing my best to correct some happy little mistakes. After that I applied a flat black guide coat to see how it was coming along.

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She is far from perfect, but not terrible either. A little more sanding is in order as well.

Sometime in the next few days we will use JB weld to fill in the horse on the magwell, and then add some Moly Resin to make it look right.

Posted: 4/19/2020 7:33:22 PM EDT

[#9]

Quote History

Quoted:
Nice tutorial.

View Quote

Thanks! I hope it helps someone try this for themselves.

Posted: 4/19/2020 8:50:14 PM EDT

[#10]

Very nice. Thanks for sharing.

Posted: 4/19/2020 11:19:54 PM EDT

[#11]

nice, this is how the old timers had to make retro lowers before NDS.

Posted: 4/20/2020 12:46:22 AM EDT

[#12]

Very nice work, especially with basically just hand tools. I've done two 80%s, but had access to a mill as well. It still required a lot of handwork with files and sandpaper. Are you going to round the bolt catch bosses too?

Posted: 4/20/2020 1:10:31 AM EDT

[#13]

Handmade receiver looks more realistic if done correctly.
Great job sir!

Posted: 4/20/2020 4:59:00 PM EDT

[#14]

Great job on the conversion to a A1 lower

Posted: 4/20/2020 6:12:19 PM EDT

[#15]

Hey thanks a bunch for the compliments ya'll, I do appreciate it

And I probably should round the bolt catch lugs!

Posted: 5/3/2020 6:48:56 PM EDT

[#16]

Took me a while to pick this one back up

Anywhoo, next we will fill the Anderson horse logo with JB Weld. Mix as directed and apply to the logo that you want to remove (also works well for pesky right hand side fire/safe marks). Be sure to press the filler into the logo, so as to push the air out.

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After letting it cure for a full day, you will want to cook the receiver in the oven at 300 degrees for an hour. This is what it will go through when the MolyResin is applied, and the JB will shrink some.

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Posted: 5/3/2020 6:56:43 PM EDT

[#17]

After cooking, the receiver is ready to be sanded. Go easy, as you can dig into the JB a whole lot easier than you can the aluminum. If you uncover an air pocket, re-apply the JB and cook it again (if you look close you can see a spot where I had to do this). A nice way to get a flat surface is to wrap your sandpaper around a flat file. Also, don't apply too much pressure or you can leave some pretty deep scratches in the aluminum.

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Now is a good opportunity to do some final touch-up before spraying with MolyResin. Using a flat file, I went ahead and removed the keyhole forge at the rear of the trigger area, and did a little more work at the back of the receiver.

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I also went ahead and rounded the bolt catch lugs. I did this with the Dremel sanding drum, files, and sandpaper.

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Posted: 5/3/2020 7:00:55 PM EDT

[#18]

After a coat of MolyResin we see the final results. It doesn't look as nice as the NDS or the Brownells receivers, but it was a cheap to do fun project.

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Posted: 5/3/2020 7:23:45 PM EDT

[#19]

Very nice job. That's how most everyone here used to do it before NDS. I've always recommended this while on NDS waiting list just to get up and running with retro parts investment. Retro upper / lower receivers no one else even comes close to NDS. Well worth the wait.

I generally just use A-2 current production and prefer no markings like Spiders and Snakes but I've ground a few. Is a little labor intensive. Anderson probably the best actual correct dimension spec FCG pin hole locations out of all of them. Some of their other features can leave a little to be desired but never seen the first FCG pin location issue personally and calipers say dead on spec and I've used a lot of them. Can't say that about some of the others but no one is perfect. Not to mention they cost $40. I'd rather use one of those for a precision shooter than most the others personally. I can fix a boggerred up trigger guard pin hole rather quickly, face / true a receiver if actually needed but hard to fix a FCG pin hole out of spec, not to mention possible safety issues. Again great job and attention to detail. Hope it shoots great.

Posted: 5/3/2020 7:39:19 PM EDT

[#20]

Thank you sir, I really appreciate it!

Not really sure what I am going to do with it. I do have a de-milled A1 parts kit on the way, but not too sure yet.

I hope this post helps some of those new to the retro world to try something different. It can be quite rewarding to modify some parts yourself, to get a bit more retro

Posted: 5/3/2020 8:58:09 PM EDT

[#21]

Kinda wish I had bought some kits to replenish Colt parts stock if nothing else due to unavailability but I've been down that road with better condition also. Think everyone who bought current kits at lower pricing even though condition not as advertised say with Grade A or B was still more than happy. Covid-19 has put a monkey wrench in quality manufacturing for sure but it's good to see they are trying to help Amercan's. Helps those selling functional but not true milspec stuff if nothing else. I wish I had bought a Colt 901 when $1800. Just saw one on Gunbroker at $2700 plus with days to go. People want what they want and ice cream comes in different flavors for a reason.

Posted: 5/3/2020 10:16:06 PM EDT

[#22]

Great job!

Posted: 5/4/2020 2:34:28 PM EDT

[#23]

Nice. I have an 80% that I started doing this on last summer, but couldn't decide how to do the little reinforcement area at the back of the receiver. I like that cone bit idea.

Posted: 5/4/2020 4:34:23 PM EDT

[#24]

Really great work!! Looks beautiful

Posted: 5/4/2020 6:12:40 PM EDT

[#25]

Thanks again for the compliments!

Posted: 5/4/2020 6:14:27 PM EDT

[#26]

Quote History

Quoted:
Nice. I have an 80% that I started doing this on last summer, but couldn't decide how to do the little reinforcement area at the back of the receiver. I like that cone bit idea.

View Quote

Give it a whirl, and definitely let us know how it turns out!

Also, this is just the way that I figured out how to do it. I'd love to hear what others have done/what has worked for them.

Posted: 5/8/2020 10:08:06 PM EDT

[#27]

It looks great profile-wise, but odd because it says "Anderson". I do like how you removed the Horse. I'd considered retro-ing my Anderson before seeing this, but was wavering. Seeing how well yours came out, I think I'm going to do it.

Like I had typed earlier, I've done two 80% lowers already, but I had the benefit of access to a mill. With the mill, I cut the corners at the pivot pin lugs, the very top sides of the receiver extension "ring", and rough out the lower side "pockets" behind the takedown pin. Everything else is with a pneumatic pencil grinder and Dremel steel burrs, followed by files and sandpaper. I have just about all of the Dremel burr shapes, but mostly use the round, and small flat-end cylinders. I'd post photos, but don't have a working Imgur account yet.

Again, you did a very nice job!