Gunsmithing AR Lower Jig for Mill

[Yasherka]

I just returned a Noreen Firearms jig to Brownells that ended up ruining two lowers. The plate was offset to the left despite my best efforts and the left wall of each lower was half the thickness of the right.

I now have a small mill

Grizzly G0761 - 10" x 32" 2 HP HD Benchtop Mill/Drill w/ Power Feed & Tapping - Grizzly Industrial, Inc.

<h1>G0761 10" x 32" 2 HP HD Benchtop Mill/Drill w/ Power Feed & Tapping</h1><h2>This Heavy-Duty Mill/Drill with Power Feed has it all!</h2> <p>Looking for a Benchtop Mill/Drill with tapping capabilities that can rival the accuracy and rigidity of a knee mill? Then take a good look at this...

www.grizzly.com

and am wanting to do the lowers on it. Is there a decent jig out there designed to be used with a milling machine? I'm concerned about the pressure of the vice on it as teh Noreen was completely unsupported on the bottom.

 

[2aBaC̶a̶]

Ive been using Juggernaut tactical jig in a mill. Sandwich some 1/8" packing foam on the sides of the lower to prevent marks.

 

[Yasherka]

Ive been using Juggernaut tactical jig in a mill. Sandwich some 1/8" packing foam on the sides of the lower to prevent marks.

Thanks, it looks pretty well made. I assume you aren't having an issue with the bottom portion being crushed?

 

[2aBaC̶a̶]

No, it would take an excessive amount to do that.

 

[LtDan47]

If you are using a mill why the heck would you use the top plate at all. I have three jigs, 2 vytamenc and a TMI. I scribe the cut area remove the top plate plug drill then mill. My mill has mill stops and I use them to go inside the scribed marks. You can see the cutting and how close you are to the edge which I believe is .100" I also made a disc the sits in the trigger guard area to keep my mill vice from squeezing the jig and possibly warping it. I also put stand off collars on the clamping bolts to keep the jig tight.

 

[GH41]

Off topic slightly.... Why do you guys fool with 80% lowers when good finished lowers are availible for peanuts??

 

[mudpig]

Off topic slightly.... Why do you guys fool with 80% lowers when good finished lowers are availible for peanuts??

Because BIG BROTHER knows where all those serialized peanut priced lowers reside!!

 

[powdahound76]

That.
Some either live behind lines or in a place they see the state wanting to ban or restrict them.

80% AR and Glock 19 80% available for cash locally...... so I hear

 

[Yasherka]

If you are using a mill why the heck would you use the top plate at all. I have three jigs, 2 vytamenc and a TMI. I scribe the cut area remove the top plate plug drill then mill. My mill has mill stops and I use them to go inside the scribed marks. You can see the cutting and how close you are to the edge which I believe is .100" I also made a disc the sits in the trigger guard area to keep my mill vice from squeezing the jig and possibly warping it. I also put stand off collars on the clamping bolts to keep the jig tight.

Thanks! I don't know a whole lot about machining but have always wanted to learn. Hence the mill and the classes I am taking. I like the idea of just using the top to scribe the opening.

I don't have stops for it so am using the handwheel graduations for depth. I'll probably pick up a quill DRO in the near future to speed things up

 

[Yasherka]

Off topic slightly.... Why do you guys fool with 80% lowers when good finished lowers are availible for peanuts??

@powdahound76 gave one answer, which I am all on board with. But I also view it as a learning process. I am an official "old fart" but I love learning new things.

 

[Cornerstonearmory]

Because BIG BROTHER knows where all those serialized peanut priced lowers reside!!

No they don’t. There’s not a gun registry currently.

 

[Yasherka]

No they don’t. There’s not a gun registry currently.

...that you know of.

 

[skinnj1]

1-2-3 blocks and an indicator should be all you need assuming you have a mill with a vise that has been indicated in and clamped down....

 

[Lapuapalooza]

CNCGuns.com jigs are good to go.

 

[Blutroop]

It’s a shame if your not careful it costs more to buy all the parts and diy..

 

[Cornerstonearmory]

...that you know of.

Yea, I do know. Have you ever ran a NICS check? No firearm information is submitted. Only applicant information. And the 4473 is only held on to by the FFL. DOJ only refers back to that paperwork if there is a question about the transfer.

And at the state level, well they can barely print out a drivers license when you provide them with all of your information.... soooo, remove your tin foil hat.

 

[Blutroop]

Yea, I do know. Have you ever ran a NICS check? No firearm information is submitted. Only applicant information. And the 4473 is only held on to by the FFL. DOJ only refers back to that paperwork if there is a question about the transfer.

And at the state level, well they can barely print out a drivers license when you provide them with all of your information.... soooo, remove your tin foil hat.

Well I stayed in a holiday inn once.. wasn’t there something going on with the 4473’s in Texas during fast and furious? Not trying to sound like the para noid person I am but..

 

[powdahound76]

And how do they know where a gun was purchased from during a commercial break on a TV show?

Really though. Someone in a nondescript office building somewhere knows.
If you dont think they have a darn good idea what you have, you arent paranoid enough and should go watch more CNN.....

 

[skinnj1]

Imo, using a commercial "router jig" with a mill is counterproductive. You do not need it. It is a lot like new shooters wanting to go to a 25lb, light recoil, light trigger prs rifle- it does not allow/require you to learn the fundamentals and build you abilities.

Buying more mill specific tooling (and learning how to use it) will get you further down the road to greater capabilities than buying a jig.

If you do not have a blueprint yet, google one off the net and stare at it a while.

If you are new to machining you might consider downloading Ray Brandes (ray-vin) excellent tutorial. He goes as far as breaking down the coordinates that you need to machine your pockets to and gives you his fixtures blueprints that he uses on a 0%.

For an 80% you do not have to make it as complicated a setup as he does simply indicate the "deck" of the reciever flat as the reciever is set in the vise between 2 1-2-3 blocks like so ( safety stops above the block):

Now find the centerline of the reciever above the 1-2-3 blocks with an edgefinder (measure width of blank, edge find, zero dial/dro, move in 1/2 the width after accounting for your edgefinder radius)

Now you have a y axis zero. Next find the x axis zero relative to a gauge pin (or other approximately .250-.251 round thing you stick in the front pivot pin hole) by using a edgefinder as above (zero dial/dro once you find the edge and move in .125+radius of edgefinder from the front edge of pin you are locating from, reset zero)

Once you have the x and y axis zeros you can "paint by numbers" using the info off of a blueprint or Brandes tutorial to make your pockets and trigger slot relative to the front pin.

Next flip the reciever on it's side, buffer tube and .750 radius portion of lower outside of the vise jaws and indicate it level in the vise( the deck and bottom of a 80% should already be parallel to each other). Short of using a cheater bar on a kurt vide you shouldn't damage the reciever. Now find the front pivot pin location . Methods vary from as ghetto as eyeballing a drill bit in a chuck, to using a DTI to indicate the hole (what I reccomend a begginer to practice), to using a tool makers button and edge finder , to using a co-axial indicator or any of the other ways a machinist could skin that cat....

Once front pivot pin is found zero x and y axis move over and drill and ream the trigger/safety/hammer holes per blueprint

Done, no jig needed, no need to worry about jig compatibility with your "billet 80" or buying another jig to do a ar308 lower or pcc lower or....

 

[skinnj1]

Yea, I do know. Have you ever ran a NICS check? No firearm information is submitted. Only applicant information. And the 4473 is only held on to by the FFL. DOJ only refers back to that paperwork if there is a question about the transfer.

And at the state level, well they can barely print out a drivers license when you provide them with all of your information.... soooo, remove your tin foil hat.

Guess who enters all that 4473 info into a database when a ffl surrenders their books when they give up their liscense.....

 

[Blutroop]

And if ya have more money than time the guy known for the “ghost guns” made a cnc tabletop machining tool that he sells to help with his legal fees. 1500$ and it does it all for ya.

 

[Cornerstonearmory]

Well I stayed in a holiday inn once.. wasn’t there something going on with the 4473’s in Texas during fast and furious? Not trying to sound like the para noid person I am but..

Haha, hey man, at least you can admit your reasoning. That’s fair. Can’t argue with your opinion.

And how do they know where a gun was purchased from during a commercial break on a TV show?

Really though. Someone in a nondescript office building somewhere knows.
If you dont think they have a darn good idea what you have, you arent paranoid enough and should go watch more CNN.....

Not sure what that first part means. But, I’m good on CNN. Lol

Guess who enters all that 4473 info into a database when a ffl surrenders their books when they give up their liscense.....

Sooo, what happens when all those ‘entered 4473’s’ are re-sold in private sales after the fact? Where do the letter boys go then?

Listen, guys, not trying to thread jack here but I do transfers all day in one of the strictest gun law states and there is no current record book of what anyone has. Yes, the atf can go back and look at a 4473 if they want, it has to be held for 5 years, then it can be trashed. They audit our books a few times a year to look for clerical mistakes on our end. Rarely do they look for a 4473 for investigative purposes.

 

[Cornerstonearmory]

And if ya have more money than time the guy known for the “ghost guns” made a cnc tabletop machining tool that he sells to help with his legal fees. 1500$ and it does it all for ya.

He got locked up for diddling little kids, but someone else took reigns on his business.

Neat little machine: https://ghostgunner.net/product/ghost-gunner-2/

 

[skinnj1]

[QUOTE="Cornerstonearmory, post: 7877637,
Listen, guys, not trying to thread jack here but I do transfers all day in one of the strictest gun law states and there is no current record book of what anyone has. Yes, the atf can go back and look at a 4473 if they want, it has to be held for 5 years, then it can be trashed. They audit our books a few times a year to look for clerical mistakes on our end. Rarely do they look for a 4473 for investigative purposes.
[/QUOTE]
You can trash a 4473 after 5 years but not your bound books, guess who gets your books when you give up your liscense....

 

[Blutroop]

He got locked up for diddling little kids, but someone else took reigns on his business.

Neat little machine: https://ghostgunner.net/product/ghost-gunner-2/

I thought his legal troubles were over that plastic 3D printable pistol? That’s the first I heard of any kid issues? If he did that then serves him right.. does sound a little suspicious though..

 

[Yasherka]

Yea, I do know. Have you ever ran a NICS check? No firearm information is submitted. Only applicant information. And the 4473 is only held on to by the FFL. DOJ only refers back to that paperwork if there is a question about the transfer.

And at the state level, well they can barely print out a drivers license when you provide them with all of your information.... soooo, remove your tin foil hat.

You have far too much faith in the pronouncements of the FedGov. It's not tinfoil hat if there is an actual likelihood of it occurring.

But you believe what you want to believe.

 

[Blutroop]

You have far too much faith in the pronouncements of the FedGov. It's not tinfoil hat if there is an actual likelihood of it occurring.

But you believe what you want to believe.

I have a solution that should make both of y’all happy. Cornerstonearmory, if you could send out a few of your personal registered ar’s to me and yashurka and anyone else who still has a tin foil hat (since you have so much faith in the system) and we will promise not to use em until and if the gov does come for em.. and we will return a few to you after they clean out your house.. ok now let’s shake hands..

 

[Blutroop]

You know you want to sell a few to Rusty Shackleford.. and Mike Hunt..