Sunday, July 29, 2018

Laminated gun parts

This week on Ghetto Gunsmithing - a laminated gun part.  I saw this on ebay.  The seller says it's a Colt, but looks like a homemade replacement for a .22 single action of some sort.  But it is still interesting, nevertheless.  Instead of machining it with a milling machine, the part could be cut out with a jigsaw and welded or screwed together; perhaps the individual sheet is filed down to fit before final lamination.

Builders on weaponsguild have been using the laminated design for gun parts with success already - so if it works, go for it, I say.



Tuesday, July 10, 2018

DIY nightvision scope kit (link)

Saw this on Amazon while looking for a mounted IR illuminator.  A home-made nightvision scope kit.

DIY night vision scope


It works on the principal that most cheap consumer electronic photo cameras have innate nightvision capabilities, but are fitted with filters to get rid of unwanted light sources (such as infrared).  From what I can tell the kit is just a stripped camera sensor mounted to the scope, an IR illuminator with cheap-o mount, and a battery pack/LCD screen combo that mounts on top of the scope.

It's a neat kit and I am a fan of home-made stuff, but I feel like such a contraption is unwieldy for any rifle.  I considered buying it just to slap together and use it as a night vision viewer thing, but you can buy a NV monocular starting at $90.  Curiously, there is also a 5x monocular with a rail underneath and recording capabilities for $150.  For $300 you could get yourself a proper entry-level night vision scope (which has been known to go on sale for $250 at times).

Tuesday, May 8, 2018

M73 Machine Gun - A Forgotten Weapon (Video)

m73 barrel extension ebay
$45 - Grab it!
I saw this weird thing on eBay - It's a locking frame of an M73A1 Coaxial Machinegun, also known as the M219 tank gun.  These shortlived weapons were used in the 1960's for mounting onto tanks and were quickly replaced by the M60 due to these not being very reliable guns.  The design is interesting - the barrel extension housed all major components - barrel, bolt, feed mechanism - so the design is simple and has a small profile.  It's said to be the most compact action of any belt-fed .308 machinegun (at the time, maybe even today).


Preventive Maintenance Monthly M73
The Preventive Maintnance Monthly article on the M73
Things I learned about this gun:
  • Fired from an open bolt/fixed firing pin
  • Recoil operated
  • Used some kind of rotating arm/rammer to send rounds into battery
  • The rammer rotated on the barrel extension assembly
  • Feeds from left or right, using disintegrating links
  • Quick-change barrel simply drops into extension
  • No bolt - uses a wierdo breech block - like a falling block action, I guess.
Information is hard to find on this.  I think a few people on the 1919a4 forums have complete kits of this.  No known semi-automatic versions of this exist, and as far as I can tell, no Class 3 MG owner has a complete one.  Seems like an interesting project, but also complex.


Still trying to wrap my head around how exactly that bolt face engages the cartridge.  It's hard to find a good diagram of this and the various drawings of this have the breech mechanism oriented in weird angles.  The jist of it is that breech block contains the firing pin and sidles in somehow to lock the barrel to the extension and fire the cartridge at the same time.
Preventive Maintnance Monthly M73 breech block
M73 breech blocks - how do they work?
Parts are available through GunPartsCorp and Sarco, though I'm mostly sure that top cover components and other stuff are missing and not available.

For $45 with a presumably complete arm assembly, that barrel extension might be a good deal considering Sarco and GPC are selling them for $200.

Related Reading
M73 Article on Wikipedia
Small Arms Review - The M73/M219 Machine Gun: Mama's Ugly Baby
Tank and AFV News - "The sad story of the M73 coax machine gun"
GunPartsCorp - M219 parts
Sarco - M73 parts

Sunday, April 15, 2018

Parts list: $311 AR15 build (with links)

Pointless anecdote: I remember first hearing about the "Assault Weapons Ban" being lifted in 2004.  It was on a videogame forum where our resident gun nut was showing off his AR-15 with a brand-new collapsable stock.  I foolishly asked if the ban ending meant machineguns were legal - I didn't really know much about guns except what I'd seen in Metal Gear Solid, Counterstrike, Rainbow Six and a handful of shooter games where guns were realistically depicted (for the time).  The gentleman informed me about his AR15, what was legal and what was not, and I became interested in owning something the government didn't want me having.  I learned about FFL transfers and soon found myself ordering a brand new WASR-10 AK type rifle to my local gunshop within the following month.

It was a cheap Romanian AK I paid $300 or so.  At the time, an AR15 cost roughly $700 or more for a low-end model.  Roughly thirteen years later, even with inflation, you can occasionally find a cheap AR for under $450 (Anderson AM15, stripped, $410; Andserson AM15, optics ready, $440 are some examples) while a low-end, matched serial AK parts kit cost $400 or more (unmatched serialized kits $319 at Apex).  Funny how times have changed.

Yao Ming, cool story bro
Yeah, cool story bro.  Where was I going with this?

It's ironic how the AK was a weapon that was meant to be built cheaply and quickly, and now every machine shop in the US is cranking out AR15 parts to the point that it is now the more affordable weapon.

I think it's possible to go cheaper than $400 if you build from individual parts, sourcing from different online stores that have deals and sales.  This doesn't take into account shipping charges.  Non-essential parts like butt-stock were not factored in because the AR15 technically runs without it (though I did leave sight option in the list.  No real scientific reason why, I guess).

It would be a waste of time to link to every part that's on sale right now because sales come and go, small shops go out of business, and sometimes inventory just gets sold out.  This list is just to give a general idea on what a good deal is and what's a normal price (as of April 2018).  I check Gun.Deals almost daily, specifically the parts section to see a list of gun parts that are currently on sale.  For a more comprehensive list of links check the end of the post.

THE LIST
  • Complete Buffer Tube Assembly - DHGate Buffer Assembly ($20.58) - Free shipping from DHGate, along with bulk discount pricing.  Comes with buffer, spring, tube, castle nut, and back plate.  If you see an American company selling a complete buffer assembly for $25 or less, chances are good that they're actually Chinese so you might as well buy it straight from the source.
  • Lower Receiver - Modulus Arms 80% Receiver ($40), Noreen 80% Receiver ($40) - You can order a stripped 100% lower through an FFL for $30-50 (plus additional transfer fees).  I've never seen one at a gun shop or gun show sell for less than $60.  It's probably cheaper online if you check on GunDeals.  You can also mill out your own 80% receiver for $40 - with a jig and drill press, of course - and if you don't have a jig, make friends with someone who does!
  • Complete lower parts kit - Gorilla Machining ($40) - The absolute cheapest COMPLETE ar lower parts kit I've ever seen was $35 with $5 USPS flat-rate shipping.  So that's $40.  I don't think it's possible to get the price any lower than that.

    The reason why I believe this is because I was going to list the individual parts so you could make your own LPK, but the cheapest price of a stand alone fire control group is $25.  That means there is no way to buy the rest of the parts individually and keep the total under $40.

    UNLESS - IF you made your own grips from scratch, fashioned takedown pins from 0.250 machine screws/rods - AND there is no safety and detents/springs, which I guess is important to all you normies with good taste.  It's pretty ghetto but it works, but the savings was a measly $7.  I didn't want to turn this post into a "how to make AR15 parts from scratch" tutorial, but I will probably make instructions on that someday.
  • Stripped Upper - Gorilla Machining Blemished ($35), ATI Polymer Hybrid ($35) - If you check on Gun.Deals, you can find a blemished upper for $30 or even $25 for an un-anodized one on rare occasions.  Blemished means it's just cosmetic defect, and has no affect on function. You can also take a chance on a polymer upper from ATI.  It is re-enforced with a metal insert.  Stripped Anderson uppers are usually $45-$55.
  • Barrel Nut - MidwayUSA Barrel nut ($6), Chinese Free Float Tube 4"-15" ($15-$35) - A barrel nut by itself can be had for $6 but you will probably want a handguard. For $15 you can get a Chinese-made, 4" free float tube which includes a built-in barrel nut. The 7" handgaurd cost $23 and the price increases further with length.  Free shipping because Chinese.
  • Sights - Fake-ass Magpul BUS ($4.36) - Sights are optional - I'm assuming this weapon is being used to mass execute political dissidents, infiltrators, and enemies of the peace, but maybe you want to aim.  If you check ebay and search "front rear sights" you'll find a bunch of $1-$2 sight sets that are actually molded airsoft sights that don't have crossbolts to lock into the rails, but with modification they would probably work.  For $4.36 you can get these slightly nicer plastic sights with with the cross-bolt built-in and a box that says "Magpul" on it!
  • Bolt Carrier Group - Palmetto State Armory ($79.99) - Standard, mil-spec, complete bolt carrier group, not magnetic particle-tested (James Yeager, internet gun expert, says MPI is a waste of money anyways).  I was seeing surplus and used BCGs and some new ones on sale for $65 as of December 2017, but I think the prices are returning to normal.  New BCGs cost normally cost $90-$110.
Cheapest bolt carrier group: $65, December 2017
OMG look, I'm not making this up!
Total price ~$311, rounded up to the nearest dollar, based on parts that are actually available now.  But suppose you went full-ghetto and made a lower receiver from scratch, used a FCG and machine screws in lieu of a complete LPK, didn't use a handguard, got your hands on the $25 upper, and found one of those $65 BCGs?  That's about $225 for an AR15.

I wasn't trying to make this an AK vs AR15 comparison, but on the subject of AK47s, you could probably piece one together by sourcing parts from different online shops, but overall it would cost more:  Front and rear trunnions are $110-$50, respectively; BCG assemblies are over $100 now; you're lucky if you find a barrel for $60 these days; gas blocks and rear sight blocks are $40-$60.  The days of cheap AK47s are officially done.

And that's about it.  I didn't work today and I drank, like, 50 Mountain Dews plus a pot of coffee and spent, like, 3 hours at the gym, I think I could bite through metal right neow - that's why this whole post is a jumbled mess, but I hope at least this was helpful to somebody.  If not, maybe humans in the future will look back at this and be like "Hey remember when we used those $300 AR15s to fight hippies in that civil war the democrats started?  Those were the good old days."
Shhhhheeeeeeeeitt
LINKS

There's a hundred online gun accessory stores that sell AR15 parts.  While I can't possibly list them all, as long as you're not some helpless old person and can do a simple google search, you can probably find more of these places easily.

Gun.Deals for everything.

I wasn't originally planning on listing PrimaryArms, but they kept popping up on my radar during my last minute research for cheap gear, so they get a cookie.

If you you're a gun guy you already know about MidWayUSA and Brownells, but I'm listing them here just in case AR newbies are watching.  These online stores usually sell at or slightly above the average price, and I haven't ordered from these types of websites in a long time, but they're a good source of parts if you need something in a pinch:
MidWayUSA is pretty quick to process and ship and they usually have a discount of an undisclosed quantity for your birthday if you're registered with them and had an account with them for a while.
Brownell's has consistently had a 10% off + free shipping after ThanksGiving and Christmas.
JoeBobOutfitters has a smaller selection of stuff but sometimes has cheaper things (and a 5% military and LEO discount).

Chinese sites I use are DHGate, and AliExpress which are useful for stuff like grips, handgaurds, rails, scope mounts, and stocks and have bulk order discounts.  eBay also sells these Chinese parts listed under the hunting section, but don't directly name the AR15/M4 (search "free float tube," "gas block," etc...). 

Note: DHGate and AliExpress might state "airsoft only."  This applies to cosmetic things handguards, gasblocks, charging handles, rails accessories etc.  You should be able to tell if it will work in an AR15 just by looking at it.  Obviously an airsoft BCG or barrel won't work in a real AR15.  The "airsoft only" statement is usually there to skirt international weapons export laws and all that other crap.  You won't get in trouble for ordering this stuff in the US because that only applies to sellers/manufacturers/exporters.  Also because 'MERICA/SHALL NOT BE INFRINGED/MOLON LABE, etc...

Also I have to give a holler to Gorilla Machining for good customer service and for being a quality, budget-priced parts source.

Friday, April 6, 2018

Interesting new gun parts source - "Every Gun Part"

Saw someone on WeaponsGuild link to this website called https://everygunpart.com/ and what is interesting is that they sell almost complete parts kits for common guns, minus the complete receiver.  What's more interesting is that the receivers are cleanly demilled and the pieces of receiver are included with the set, most of the time.

Not sure under what circumstance these kits were acquired from or why they needed to be chopped up (I noticed that some shotguns and rifles had the stock chopped off like something you would see on the COPS tv show).  Maybe someone acquired them at a police auction for cheap and needed to sell them but didn't have a federal firearms licence?  In that case, it would not have been worth it to do paperwork, open a gunshop, and sell the complete firearm for an additional $50-100 profit when there are willing buyers online for this kind of stuff.  Additionally, they might have had to wait 5 months for the FFL application to go through.

It's a shame that the receivers had to be chopped up, but I would love to have gotten my hands on that near complete Tec-9 kit for $150.  Or that Colt 1911 kit with demilled frame for $290 - I would have used the frame as a base for my 1911 dominator single shot or my Safari Arms Survivor and sold the rest of the parts to get my money back.  Some of those chopped up break-open single shot actions would be pretty easy to repair, I imagine.  And that Bushmaster demilled lower receiver - I could have made two seperate lower receivers from those!

AR15 kit with demilled lower receiver

Colt 1911 parts kit with demilled frame

Mac10 parts kit with demilled frame

Ruger 22 lr pistol with demilled upper receiver

Tec9 parts kit, near complete minus receiver


So yeah - because this stuff is relevant to my interests, I'm basically shilling for these guys.  I haven't ordered from them yet but they look pretty legit.  Since I've been life-sentenced to my barracks (per Marine Corps base order), NCIS is probably still watching me (I'm a very interesting guy, don'tcha know), otherwise I would have bought up all these kits to supplement my partially complete parts kits at home and sold the extra duplicate parts.

Le Happy Merchant

Saturday, March 17, 2018

Video - More home-made steel AR15 lowers

Saw these on YouTube by user bryan fox.  Homemade AR15 lower receivers made of thin sheet metal, unlike The Flat Spot's lower kits which are relatively thick (not that there's anything wrong with that - The Flat Spot's ar15 receivers are nicely made).

The first video shows that one of the receivers was assembled using screws and silver solder, for those who can't weld.  The screws were cut flush with a grinder.

The second video sheds a bit more detail on the construction.  The buffer tower was assembled via wrapped sheet metal around a buffer tube castle nut and presumably soldered or welded in place.  Seems a bit more complex and time-consuming than my proposed steel lower ideas because I think hammer forming sheet metal takes a lot of trial and error and guesswork - however, I do think that this thin sheet metal method does look more refined and less 'chaotic' than my Home Depot lower.

I'd like to try something like this eventually, and when I do I will report my findings.



Wednesday, February 14, 2018

Video - An affordable bulletproof shield

When ever I saw footage of the house-to-house raiding in Iraq on the telly, I always thought it would be useful to bring some type of personal bullet proof shield.  Around the time of the Battle of Fallujah (The first one and the expansion pack), commercial bullet-proof shields costed about $2000-$3000 - or about three times the amount an enlisted boot made per month in 2004.  Today, they still cost upwards of $3500.

The one in the video below is the Hardcore Defense Alpha Shield available for $300, available in either left or right hand and rated for up to IIIa which means it will stop most pistol rounds up to 44 magnum.  It's made of a hardened steel similar to AR500 plates.  The Demolition Ranch video demonstrates that it's capable of stopping a little bit more than that, although I would have liked to have seen 7.62 Tokarev, 7.62x39, 5.56 Nato and other rounds used by our enemies.  Pretty sure .308 and 7.62x54 would blow right through it though.


Interesting commentary on getting struck by
bullets with the shield equipped.
I know that personal weapons aren't typically allowed by regular troops, but I don't see why a personal shield would be disallowed, other than being too big, cumbersome and probably blocking the user's field of vision somewhat.  Some modifications i'd like to see made to this would be to make a smaller version of this.  Maybe one with straps that can be worn on the back like a backpack, kind of like Captain America, I guess.  Also make it wrist-mounted and make it so you can use a rifle with it.  Oh yeah, add some molle loops - because you can never find a molle loop when you're mad.  Aditionally, the reason for the molle is that if you're gonna wear it like a backpack, you might as well carry gear in it and honestly - you'll probably look like a mall-ninja idiot carrying a shield around.  The molle and straps would be to disguise it as a backpack.
 
Strike Industries almost makes something that matches my description - The SI Simple Plate Carrier.  It was $40 when I bought it on Amazon but now it's $135 - and it doesn't even come with a plate.  Those lousy cunts.  Using it as a shield is dumb - the shield handle is quite flimsy and I'd be pissed if I spent $135 + shipping on this garbage.  I pretty much use mine for toting my tablet or small laptop to Starbucks.

Enjoy some pictures of bullet proof shields that I found on the web via Google.
 
ballistic mat shield
Ballistic mat.  I guess someone somewhere has a use for it.
gign soldiers with shield
Tactical frogs with shield.
Hongkong police with shield
Hong Kong police with shield.
police with ballistic shield
Looks interesting.  I'd want one in metal.
Robo Level3 ballistic shield
Robo Level3 ballistic shield.
counterstrike bullet proof shield
Remember bullet proof shields from Counterstrike?
They're back.  In pogue form.

Sunday, January 7, 2018

Gaming - Trayvon Martin Simulator

Ayo, hol' up.  It seems in late December 2017, a game called One Dark Night was released on Steam for free.  As far as I can tell, this is not actually a game, but a recreation of the night Trayvon Martin was killed in a classic case of self defence (as proven in a court of law by a jury of citizens).
Produced exclusively from real recordings of 911 calls, witness trial testimony and architectural drawings that provide the exact layout of both interiors and exteriors of the condo complex, One Dark Night tells the story of the day teenager Travyon Martin was shot and killed by neighborhood watch volunteer George Zimmerman.

By anchoring the piece in accurate and unassailable elements, the user becomes transported inside a reliable, albeit virtual, version of the story as an eyewitness. One Dark Night breaks new ground on multiple levels, including through audio carefully cleaned by forensic specialists Sourcesound and Primeau Productions, with the latter asserting that the reconstructed audio indicates George Zimmerman cocked his gun just before he gave chase. 

I have not played it, nor do I plan to - it seems there's a lot of games on Steam that exist solely for shock value and/or some kind of artistic statement.  Judging from the game's description alone, there's a lot of speculating and assumptions that seem to favor Trayvon's side of the story.  At least the reviews are kind of funny.







Buffertube towers and the $2 receiver

Rants on the Flat AR Lower and Buffer Tube Interface Dilemma
Also – is a $2 lower receiver possible!? (The quick answer is yes, see halfway through post below)

Note: This article is more or less a continuation of my "Home-Depot" lower receiver series which can be chronicled here and here.  My interest in this project continuously waxes and wanes over time.  I wrote this back around June 2017 and added to it over a period of months so this article is kind of a disjointed mess, the links are a little old and the prices are not quite up-to-date.

An ideal starting point for a flat AR.
Concept by elmgrove1765
One of the problems faced with the non-milled AR lower (i.e. a lower made from metal flats, wood, or other laminates) is that no one specifically makes a threaded block to interface the buffertube to the receiver flats.  The Jack Squat Flat Lower requires a lathe to thread the buffer tower piece that comes with it, in addition to welding, so that alienates the typical garage builder who doesn't have access to a lathe or welder.  An AR15 buffer block (pictured at right) would be ideal for the home builder because you could just drill & tap the holes of the sideplate and screw it together.

Recently 80% lowers or even 100% lowers have come down as low as $25 in the past month.  So why would anyone need to cobble together a flat lower when you can get something solid for cheaper? Several reasons:
  • A cheap “throw-away” receiver can be smuggled inconspicuously in pieces and the upper sent through the mail (this would probably only make sense in the US/Canada since in most other countries the law considers that the barrel is the gun, not the receiver)
  • Rapid mass-production of lowers using cheap scrap or sheet metal in an underground, budget workshop
  • Milling out solid lower receivers on a drill press is vastly more time-consuming compared to drilling holes on precut pieces of thin metal sheets.
Stock adapters, left to right: Rifle Dynamics, KeepShooting,
Shockwave, and USMachineGun
 So here is quick rundown of threaded stock adapters for various other weapons where the user would want to use a collapsable M4 stock, but these also happen to work as buffertube towers (or buffer trunnion, if you want to call it that) for our flat lower.
  • Clamp-on, single point sling attachment adapter (requires two castle nuts).  Aluminum.  This is the cheapest solution at $3 for the adapter plus $1.80 for each castlenut, totalling $6.60 for the assembled unit.  This is used as an attachment for adding a sling to a buffertube.  It has a cup where it would slip over the castle nut, but as seen right, it can be modified and used to interface the flats to the buffertube.  The sling loops may need to be cut off, but I got away with leaving them intact.  I’ve actually rigged something even more ghetto (see further below) that doesn't require castlenuts or adapters, but this is the cheapest thing commercially available if you don't want to drill up a buffertube.
  • Another Clamp-on Sling Mount - $8.70, aluminum.  Comes with built-in sling mount that will need to be cut off.  Also requires a castlenut.  Seems better made than the one above, but I have not tested this out.
  • MAC-10 stock adapter of unknown origin - I like these - they’re steel, they’re thick and they’re $30.  I don’t know who makes them or how much KeepShooting has left in stock, but they look nice.  They have flat sides and with plenty of room to mount screws onto them.  KeepShooting has 15% off codes every couple of months during special holidays, so that's worth considering.
  • Shockwave Mighty Mount M11 adapter - $35, aluminum, and it has wide surface area for sideplate attachment options.  Might have to re-profile it to mate with the upper, or you could install it backwards.
  • AngryGunAirsoft SCAR adapter - $40, aluminum.  It’s for airsoft but it uses standard AR15 threads.  It’s a bit too long, length and height-wise, but it seems like it could be put to good use with the right modification.  A bit expensive for me to risk experimenting with dremelwork, but I like the wide surface area.  This could be the basis for some kind of takedown ar15 where the buffer assembly can slip on and off.
  • Midwest Industries Heavy Duty QD Sling Adapter - $50, aluminum.  Wide surface area and lots of metal.  Might need a buffer tube with lots of threaded space.  Have not bought or tested this.
  • RifleDynamics AK adapter - $65, aluminum.  No reason to buy this, but it’s there if you want it.  I don’t think there’s enough metal for my project’s intended use.  It's a really nicely made adapter for the AK.
  • USMachinegun M11 Adapter - $66, aluminum.  This is a bad price for what this is.  Even as an actual M11 stock adapter, it feels like something that was made in China and should be sold on ebay for 10 bucks.
  • photo by backbencher,
    Hera Arms CQR stock
  • Hera Arms CQR stock - $120, polymer.  I am definitely not spending 120 bucks on a throw-away receiver - but again the option is there if you’re into that, I guess.  This idea was from a fellow on the Ar15.com forums named backbencher who posted a picture of an AR15 FCG testing fixture connected to a buffertube via this stock, with an upper mounted to it.  He planned on putting a 5.7mm P90 upper on it, which would solve the problem trying to fit a STANAG magazine well.  This stock is interesting in that it could be useful for repairing AR lowers where the buffer tower has snapped off.
Finally, this is an even cheaper option than the $6.60 clamp-on sling adapter with castlenuts assembly that was first mentioned above.  Using the following method, the receiver doesn’t cost anything but the price of the metal you use.  I am not going to factor in the cost of a carbine buffertube since you would presumably be buying one anyways, however, it does require cosmetically permanent modification to the tube.  Carbine buffertube kits right now sell for less than $20 on ebay or Amazon.  Also check Chinese wholesale websites like DHgate where it’s currently 14 bucks for the kit - that is if you don't mind waiting a month for delivery.  Or you could just get the tube by itself which I've seen sell for 5 bucks at Copes Distributing once.

A six foot length of 1/8” x 1.25” aluminum costs about $6.00 from Tractor Supply, which you could make several lowers from.  Steel would be better, but I wanted to try aluminum first for ease of drilling and cutting.  You simply bolt on the long sideplates to the stock adjustment rail, and locate the holes for the front and rear takedown pins and FCG (I go in depth about aligning the tube with the upper and locating the holes on the sideplate in Home Depot lower part 2).

Step 1: Add the 1/8" x 1/2" aluminum bar to one side (I think it's half inch, might be 3/4").  Make sure it's long enough to accomodate the rear takedown hole.  It probably didn't need to extend all the way to the end like that but you probably will need to bend it later to keep it parallel with the upper.  You can use Cleco pins, small C-clamps, vise-grips, and locking pliers to hold everything in place until you screw it together.

Step 2: Use 0.990" to 0.999" dowel/rod to align the upper to the buffer tube.

Step 3: Close them together snug.

 Step 4: Check other side.  Make sure top edge of the metal bar is parallel with bottom edge of upper.  If not, you can bend the bar a little and screw it in place to the buffer tube.

Step 5: I used a short length of 1/4" tubing with a 1/8" hole to center the 1/8" drill bit.  From there you can use a 1/4" bit to widen the hole in the plate.

 Step 6:  I recommend using 1/16"  x 1.25" steel here to add rigidness and strength to the takedown holes OR 1/8" thick aluminum.  The photo shows 1/16" thick aluminum which was too thin and caused egging of the hammer holes (not shown).  It also serves as a place to drill the fire control group axis pins to.  Remember to keep it parallel to the upper.
 
  Step 7: There it is so far.  Repeat the process for the other side.  I think you can figure the rest from here.

I never got a chance to make a live-firing model, but I did make a proof-of-concept while I was on leave in May.  This was to see if I could create a stable platform to interface the buffertube to the upper.  To test alignment I installed the charging handle, bolt carrier group, spring and buffer.  With the rear takedown pin in place, the thing is solid.  You can pull the charging handle and feel the bolt-carrier ride smoothly in the buffer tube without any hiccups.

Another idea I had was to attach this to my partially complete Jack Squat Flat lower and just do away with the buffer piece that comes with it since I have no way of threading it.

Further reading:
The Home Depot Lower Part 1 - Video
The Home Depot Lower Part 2 - Instruction
Winter Soldier’s semi-auto, wood and metal lower - I drew some inspiration from here.
3d printed AR lower - 3d printable receiver in small sections, bolted together.  Perfect for small 3d printing machines, I would think.  If someone can produce the threaded buffer block and sell them to me that would be fantastic.