I've successfully built a couple of Tannery Shop 80% castings and became interested in the new 80% lowers available from www.ar15plus.com. I bought two as investments for the future. Here's some pictures and observations on them. The AR15plus web site hasn't enough pictures and the ones they have are too small to really judge the high quality of these guys.  


(above) This first picture shows the National Ordinance forged lower in front looking rather silver and the Tannery Shop forging in the back looking gray. You'll note the front pivot pin is already drilled on the National Ordinance lower which can be used to index to many of the available jigs.


(above) This picture shows another one of the differences between the two lowers. The Tannery Shop lower has the "index" hole below where the receiver extension would screw in. This ought to be a simple hole to drill out with 0.50" bit to the depth of 0.20". You'll also notice the positive stops for the safety.


(above) Here's another picture showing the front and back of the forging. The top surface looks to be pretty close but at this point I can't tell 100% as there's a bit of milling/filing to be done in the back pocket to get the take down stud of the upper to fit down into the lower. I does look closer than the casting. When I made my first two rifles this was one of the most time consuming portions of the build matching the rounded curve on the rear of the lower to the upper.


A close up of two areas of interest. On the lower on the left you can see the "flaw" on the lower edge of the magazine well. This is actually the result of the forging process and can be filed down a bit if it bothers you, it doesn't bother function at all. The lower on the right displays the pre-drilled holes for the trigger guard. Some builders have had problems with these but on my castings I had no problem at all using sharp drill bits and a piece of wood 0.450" large stuck between the ears to support them during drilling.


(above) This photo shows the details around the bolt catch release and the magazine release. All of theses difficult slots are cut to proper size. Only left to do is the bolt catch retaining pin hole. The quality of the satin finish of the lower can be seen with the soft glow on the magazine well. The touch is silky smooth and ready for finishing.


(above) A view looking down into the magazine well and trigger assembly. The lips of the mag well are finished and a USGI magazine can be barely forced into the well. This is good and bad. Good because there's not a whole lot of work to be done here, bad as this lower would make a bad single shot for use under a .50 BMG in California. Of my two samples one is large enough that magazines fit, the other isn't. As I said early the back end of the trigger assembly needs to be milled out enough to let the lower's stud drop down into the hole. One of my Bushmaster uppers measures 0.50", the hole measures just 0.460. On the Tannery Shop lower this work isn't needed. Probably take two minutes on a mill or twenty with a file.


(above) Here's the belly of the lower. Note the magazine well lips are already tapered. You can again see the forging seam running across the bottom - note either side where the trigger pops out.

My over all impression is one of approval. These guys are going to be much easier to finish then the Tannery Shop lower from three years ago. The finish is a nice touch and worth the extra few dollars. The top surface looks good to go after dropping the thing in my OSI drill jig. The receiver extension still requires the expensive 1-1/8" drill bit and the 1-3/16" tap but the actually drilling and tapping operation is easy enough. I think I could have one of these things ready to assemble in about an hour as long as the back curve of the upper surface is correct. Milling out the back end of the trigger assembly looks to be the most difficult part of the whole job.

Looks like I build my one last Tannery Shop lower into a single shot for a .50 BMG and use the National Ordinance ones for other purposes. The picture gallery for my Tannery Shop bulid is here: 80% Tannery Shop lower project and shows some of the needed tools.

The Tannery Shop is back in business after taking care of business in Iraq. He's now got forged receivers too at $115 as well as the cast ones mentioned above for $80 www.tanneryshop.com/ William is a good guy and one of the first to start selling the castings.

Quoted: What tools and skills are most needed to finish out an 80% lower?  I kinda like the idea of a gun that no forms were ever filled out on.  That's the attarction right?  Not a firearm therefore not nessisary to FFL transfer?

(above) You need common drill bits available at your local hardware store, a cheap drill press ($50), a 3/32" - 8 inch bit for the bolt release retaining pin hole, some duct tape , some common flat files or a mill to open the back end up a bit, and the two special tools needed for the receiver extension - a 1-1/8" drill bit and a 1-3/16" tapper. You'll need a common 1/4"-28 tape for the pistol grip hole. You also need a caliper to measure various sizes and depths. A nice blue print is always nice but you can find the files here off of the home page. www.ar15.com/content/manuals/lowerBlueprint.pdf (150 Kb Abobe Acrobat file)


(above) There are cheaper jigs out there now, this one is like three years old now and was one of the first and most complete. The jig helps you with like 8 of the 15 total holes needed.


(above) Normally the places that sell the 80% receivers have a package or several levels of packages that have tools required. The use of a jig makes cranking these things out an easy job rather than a chore. If you use a jig get some transfer punches to save wear on it.

Skill wise the processes doesn't require a skilled machinist. I'm a computer network manager and prior to that a broadcast televsion engineer. I have experence working on mechanical computers but I am not a trained machinist in any sense. You have to complete these rifles yourself - you can't drop it off at the local machine shop and pick it up completed later.

www.atf.gov/firearms/faq/faq2.htm#a7

A7) Does the GCA prohibit anyone from making a handgun, shotgun or rifle? With certain exceptions a firearm may be made by a nonlicensee provided it is not for sale and the maker is not prohibited from possessing firearms. However, a person is prohibited from making a semiautomatic assault weapon or assembling a nonsporting semiautomatic rifle or nonsporting shotgun from imported parts. In addition, the making of an NFA firearm requires a tax payment and approval by ATF. An application to make a machinegun will not be approved unless documentation is submitted showing that the firearm is being made for a federal or state agency. [18 U. S. C. 922( o), (r), (v), and 923, 27 CFR 178.39, 178.40, 178.41 and 179.105]

You'll need to be able to read a blueprint to know what size holes to cut where and how deep. I used a factory rifle to look at to see what I was doing. You'll need to read a caliper.

This is is 110% a firearm and ALL the laws on firearms cover it - you're not going to walk onto an airplane with this! It is a firearm and if you sell it you have to follow your local laws concerning such actions. Here in California that means the required registration.

The law allows us hobbiest to make these things for our own use and not as a business, I've interpepted that as I'm never going to sell one of these babies to someone - I wouldn't sell a factory manufactured firearm of mine either, that's just a personal policy.

Quoted: Thats really helpful.  I notice you said the jig helps with 8 out the 15 holes.  What are the other 7 holes and do most people do those by hand?   I guess you just apply some kind of bake-on finish once complete? Thanks again for the description and taking time to answer.

You're really going to make me work huh?

Missing holes:
Front pivot pin
Front piviot pin retaining pin
Bolt catch plunger
Bolt catch roll pin
Front trigger guard hole (1)
Rear trigger guard holes (2)
Trigger Pin
Hammer Pin
Safety
Pistol Grip
Buffer Retainer Pin
Take Down Pin
Take Down Pin Retaining Pin
Receiver Extension

Holes cut with the aid of the OSI drill rig:
Front pivot pin
Trigger Pin
Hammer Pin
Safety
Pistol Grip
Take Down Pin
Receiver Extension

(the relationship between the pivot hole and take down hole is critical - the upper just won't fit if these are a tad off. The trigger, hammer, and safety hole again form a critical set of holes.)


(above) The jig also holds the receiver "square" for the the other holes. The retaining pin holes - front pivot, rear take down, and bolt plunger are just done carefully by eyeball. The most critical of the holes not put in with the jig is the buffer retaining pin - too far back and the buffer will slam into it on the way to rest up against the bolt carrier. It's better to error a thread forward so the closing the upper is a bit difficult (the buffer will be a bit too far foward and the bolt carrier will drop down on it).


I left my castings naked and they look cool. On the forgings I might paint them with Gun-Kote.

Good post Paul. I talked to the guys at Natinal Ordnance once and they said basically if you can work on your own lawn mower you are more than capable of finishing of their lowers.

Quoted: Where do you get a $50 drill press?

Harbor Frieght - watch their sales as they drop prices quicker than Bill Clinton drops his shorts.

Quoted: I noticed that the trigger guard take down hole is scalloped, did it come that way or did you have to do it on your own with an end mill?

A scallop is something I eat with my shrimp and lobster ... I haven't touched the AR15plus receivers with a tool - that would be a felony in my state so they camed "scalloped". The completed lower "Genesis" was made in North Carolina where such things are allowed.

What's "scalloped" mean?

Quoted: HEY GUYS GREAT PICTURES AND INFO I DO CARRY 80% FORGINGS NOW WILLIAM

You're welcome to the pictures if you want to use them.

Quoted: Paul i don't imagine u just using those receivers for paper weights P.S. i would like to hear more about your AR .50 project

I was thinking about mounting them in a shadow box with a file with a sign that says "break glass in case of government oppression" but that has already happened

Quoted: i got a question can i send my reciever off to get parkerized after its finished or do i have to do it myself.

Once the firearm is able to shoot it's a firearm and you can do with it what you would do to any other firearm including have it finished. I have a bake on molly treatment purchased from Brownell's.