Master Lyndon build thread - trigger jig, thumbhole stock; .223" upper test fired 27 May

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[ARCHIVED THREAD] - Master Lyndon build thread - trigger jig, thumbhole stock; .223" upper test fired 27 May (Page 1 of 3)

Posted: 2/8/2017 8:41:32 PM EDT

Think we'll need some zip ties.

ETA: Some pics -

Hate their logo, but it's the least expensive available trigger jig I'm familiar w/. It'll bolt right onto a Hera Arms thumbhole stock.

Zip tie this on top:

ETA: JsARCLIGHT graciously sold me his Hera thumbhole stock after his review here: http://www.ar15.com/forums/t_6_2/474219_HERA-Arms-CQR-stock-and-front-grip.html

12 March - tail trimming of jig complete, sample's .22" LR upper installed. Range tomorrow.

13 March - test fired multiple times w/o zip ties.

27 May - test fired multiple times using 5.56x45mm upper, still without zip ties. Brass ejects, bolt returns to battery. Video taken of 1st shot, will be a bit before I post the link - have a wedding to attend to.

Posted: 2/8/2017 8:49:37 PM EDT

[#1]

Say what

Posted: 2/8/2017 8:53:52 PM EDT

[#2]

Needs pics

.....and the hera stuff peaks my interest, especially in sbr form

Posted: 2/8/2017 9:10:57 PM EDT

[#3]

I think I know where you're going with this. Makeshift bull pup... I've thought of it plenty.

Posted: 2/8/2017 9:20:25 PM EDT

[#4]

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Quoted:
I think I know where you're going with this. Makeshift bull pup... I've thought of it plenty.

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Not a bullpup. A rifle made of no Title 1 firearm parts. Clip the zip ties and you have a pile of parts that is NOT a firearm.

Posted: 2/8/2017 11:59:43 PM EDT

[#5]

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Quoted:
Not a bullpup. A rifle made of no Title 1 firearm parts. Clip the zip ties and you have a pile of parts that is NOT a firearm.

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I get the gist of where you're going, but please post a diagram when you have the time.

Posted: 2/9/2017 12:12:15 AM EDT

[#6]

Like the Ruger trigger jig ?

Posted: 2/9/2017 1:22:46 AM EDT

[#7]

See OP.

Posted: 2/9/2017 9:10:10 AM EDT

[#8]

Here's an AR5.7 upper shopped on War Fairy's Charon:

Imagine that w/o the magwell, and we're close.

Posted: 2/9/2017 9:15:45 AM EDT

[#9]

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Quoted: Like the Ruger trigger jig ?

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Yep.

Posted: 2/9/2017 9:16:35 AM EDT

[#10]

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Quoted:

Not a bullpup. A rifle made of no Title 1 firearm parts. Clip the zip ties and you have a pile of parts that is NOT a firearm.

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You know, their is a model with a third hole over on ebay. Even has a rear pin...

Posted: 2/9/2017 9:18:51 AM EDT

[#11]

Anyways, why not just get an 80? A little machine time and no zip ties required.

Posted: 2/9/2017 11:34:24 AM EDT

[#12]

B/c when you take apart an AR made from an 80% receiver, you still have a firearm. When you cut the zipties on this, you now have a pile of parts - none of which is legally a firearm.

And there's no machine time on this. Ziptie, load, bang!

Posted: 2/9/2017 11:38:17 AM EDT

[#13]

I would at least drill a hole for the rear receiver pin.

Im not sure how well that stock will Work without a receiver extension. Might need to put a tube in it to keep everything lined up.

Posted: 2/9/2017 11:53:39 AM EDT

[#14]

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Quoted:
B/c when you take apart an AR made from an 80% receiver, you still have a firearm. When you cut the zipties on this, you now have a pile of parts - none of which is legally a firearm.

And there's no machine time on this. Ziptie, load, bang!

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I'm no lawyer, but from some of the pretzel logic they've employed in the past, I'm thinking that ATF could find something to consider the receiver if they wanted to, most likely either the trigger jig or the stock. Perhaps not before it was assembled, but if it could be proven ever to have been assembled, then whatever part they decided was the receiver might then be a receiver forever.

Posted: 2/9/2017 11:56:14 AM EDT

[#15]

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Quoted:
B/c when you take apart an AR made from an 80% receiver, you still have a firearm. When you cut the zipties on this, you now have a pile of parts - none of which is legally a firearm.

And there's no machine time on this. Ziptie, load, bang!

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Why not use those damn steel receivers?

I like this idea. Will need to make a few holes in the jig for the zip ties.

Very intriguing indeed. Theres a channel on YouTube of this kid making crudely slapped together pipe rifles and pistols, and he's using a trigger block from somewhere but i can't remember the name. Gotta watch a view videos, i only recall him mentioning it once, but uses it on alot of his grease gun style builds.

Anyways, that trigger should work great, and be able to mount a different stock possibly.

Posted: 2/9/2017 11:58:43 AM EDT

[#16]

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Quoted:

I'm no lawyer, but from some of the pretzel logic they've employed in the past, I'm thinking that ATF could find something to consider the receiver if they wanted to, most likely either the trigger jig or the stock. Perhaps not before it was assembled, but if it could be proven ever to have been assembled, then whatever part they decided was the receiver might then be a receiver forever.

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You can make whatever you want. Just not sell it or serialize it. Or possibly take it out in public, depending on local laws of course.

Remember, you haven't committed a crime until proven do in the court of law

Posted: 2/9/2017 12:02:42 PM EDT

[#17]

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I would at least drill a hole for the rear receiver pin.

Im not sure how well that stock will Work without a receiver extension. Might need to put a tube in it to keep everything lined up.

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And the Hera stock has beautiful internal ribs that will hold 2 part epoxy perfectly. Absolutely you'll want a buffer tube. Drill a takedown pin hole in the jig if you like.

Posted: 2/9/2017 12:07:58 PM EDT

[#18]

This reminds me of the rest of your ideas.

Posted: 2/9/2017 12:23:42 PM EDT

[#19]

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Quoted:

I'm no lawyer, but from some of the pretzel logic they've employed in the past, I'm thinking that ATF could find something to consider the receiver if they wanted to, most likely either the trigger jig or the stock. Perhaps not before it was assembled, but if it could be proven ever to have been assembled, then whatever part they decided wIas the receiver might then be a receiver forever.

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I think this is the answer. ATF might decide AR57 uppers are firearms by themselves.

Posted: 2/9/2017 12:27:29 PM EDT

[#20]

Aside from the possible legality aspect, there are plenty of reasons why this wouldn't work. If you want to use zip ties to hold your pressure switches in place, fine. But using zip ties to hold operating parts that aren't even remotely close to self contained in place, yeah that's beyond dumb.

Posted: 2/9/2017 1:51:51 PM EDT

[#21]

I suppose we'll have to try it then.

Posted: 2/9/2017 2:27:02 PM EDT

[#22]

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I suppose we'll have to try it then.

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The most surefire way to determine if an idea is dumb or not.

It's just 5.7, so there's not gonna be a ton of pressure. Your hands and arms might get dirty or a little warm.

But like someone else said, you need a buffer tube, buffer and spring. You might be able to mill out the trigger block, set the buffer tube in it and epoxy that way. Then epoxy the stock onto the tube. But would be a passion getting it apart if need be.

I don't think it's dumb, i think it's weird, but kinda intuitive.

Posted: 2/9/2017 6:58:54 PM EDT

[#23]

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Quoted: The most surefire way to determine if an idea is dumb or not.

It's just 5.7, so there's not gonna be a ton of pressure. Your hands and arms might get dirty or a little warm.

But like someone else said, you need a buffer tube, buffer and spring. You might be able to mill out the trigger block, set the buffer tube in it and epoxy that way. Then epoxy the stock onto the tube. But would be a passion getting it apart if need be.

I don't think it's dumb, i think it's weird, but kinda intuitive.

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5.7x28mm probably does generate more than a ton of pressure on the bolt face. If we have the upper correctly aligned w/ the buffer tube, the action will cycle. Orion's Hammer got 3 shots out of his wooden AR lower before the bolt stuck in the misaligned buffer tube.

I don't have a $700 5.7 AR upper, so once I get my hands on a trigger jig, I'll give this a shot - a single shot, that is - w/ the 7.62x39mm upper sample gave me. Unless he wants me to try it w/ the upper I gave him. If we can get a standard DI upper to eject and then close the bolt, I think we might have something here.

I don't know when the 5.7 AR uppers 1st came out, but it's not the only upper that doesn't require a magwell in the lower. Some years back, there was a small Oklahoma company producing .45" ACP uppers that took side-fed Thompson mags. I don't believe they still have a website. The FightLite beltfed upper and the new 9x19mm beltfed upper clearly don't require a magwell, nor do the .50" BMG uppers - though I think the recoil on those would be a bit much for this application. A Can Cannon upper would be interesting to try on this as well.

I absolutely agree w/ the folks that say we need a buffer tube, buffer, & spring - the Hera Arms thumbhole stock isn't set up to take a buffer & spring w/o a tube installed. You'll probably need about 3 hands to assemble this thing, as there won't be a buffer retention pin.

Posted: 2/9/2017 7:12:06 PM EDT

[#24]

I've got that jig and a 5.7 upper. It's a 7" upper so I won't be attempting this though.

Ive already paid my $200 penalty and put it on a standard AR lower anyways.

Posted: 2/9/2017 7:15:13 PM EDT

[#25]

Yeah, having a fixed stock and not knowing where to put the serial number would be a bit of a downer.

Would you mind taking some pics of your trigger jig underneath the rear of the lower? What I don't know is if the sides of the jig are the same height as a standard lower, how wide they are, etc. We might have to trim the sides a bit to get it to line up, or we might have to add some shims.

Posted: 2/9/2017 7:25:54 PM EDT

[#26]

You're expecting a zip tie to hold the upper in alignment with the buffer tube. That's where you will be sorely disappointed.

Posted: 2/9/2017 7:28:50 PM EDT

[#27]

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Quoted:
You're expecting a zip tie to hold the upper in alignment with the buffer tube. That's where you will be sorely disappointed.

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I agree, it needs a rear pin.

Posted: 2/9/2017 7:33:29 PM EDT

[#28]

I am in...post pics

I do believe that one of the 9mm uppers you mentioned does need a magwell as the ejector is mounted in a block that goes in the magwell.

Just FYI.

I still like the plan.

Posted: 2/9/2017 8:02:43 PM EDT

[#29]

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Quoted: I am in...post pics

I do believe that one of the 9mm uppers you mentioned does need a magwell as the ejector is mounted in a block that goes in the magwell.

Just FYI.

I still like the plan.

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No parts yet. This just popped into my head last night after I posted a pic of the trigger jig in another forum for a semi-auto STEN build someone was working on. I just recently picked up a used Hera thumbhole stock from a member here. I had previously thought about using a trigger jig on a thumbhole stock, but the magwell and forward takedown boss had eluded me. Then the 5.7 upper popped into my head - don't need a magwell.

A 9x19mm upper, or any other upper that requires a magwell in the lower, is another challenge for another day. I've been tilting @ that windmill for awhile now.

Posted: 2/9/2017 8:20:33 PM EDT

[#30]

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I agree, it needs a rear pin.

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Quoted:

Quoted: You're expecting a zip tie to hold the upper in alignment with the buffer tube. That's where you will be sorely disappointed.

I agree, it needs a rear pin.

Not just a zip tie. The rear lug of the upper will have to fit in the rear slot of the trigger jig. If it's not wide enough, we'll have to widen it; if it's too wide, we can add shims - and maybe some bubblegum?

I don't have a trigger jig in my hands yet, so let us percolate this in our minds a bit, and perhaps someone will come up w/ a better idea than zip ties. I'm already considering my old stand by - super glue. Perhaps one of our agricultural or aviation experts could clue us into wire tying? Maybe we use the screw holes on the front of the jig to rig something up to the front takedown boss of the upper.

I view drilling a rear takedown pin hole as a last resort, as that will probably make the trigger jig not just a trigger jig, but a lower. That may be the only way it works, however. We'll have to see.

jaqufrost just sent me an eBay link to a trigger jig that has the rear takedown pin. Even better.

Posted: 2/9/2017 8:28:19 PM EDT

[#31]

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Quoted:
I agree, it needs a rear pin.

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Quoted:

Quoted:
You're expecting a zip tie to hold the upper in alignment with the buffer tube. That's where you will be sorely disappointed.

I agree, it needs a rear pin.

Then 3 zip ties......

Posted: 2/9/2017 8:29:03 PM EDT

[#32]

Courtesy of jaqufrost:

I am unable to recommend these nitwits unreservedly after they shipped two separate gift jigs to one recipient and repeatedly claimed to eBay that they had shipped to both recipients. They make a very nice jig - if you can get it. I don't recommend confusing them with multiple addresses.

Not my auction. ~~But probably a better solution than the Strike Industries.~~ I think this is the only time I've cursed the 3rd hole of happiness.

Posted: 2/9/2017 8:39:27 PM EDT

[#33]

Be aware, that's a 3rd hole m16 jig.

Posted: 2/9/2017 10:00:57 PM EDT

[#34]

Well crap. No 3rd hole of happiness for us.

Posted: 2/9/2017 10:12:00 PM EDT

[#35]

This is our baby.

Edited: the link broke. See below.

This is not a gun! It would be impossible to make this into any portion of a functional firearms!! It would be impossible to attached this item to any type of gun!!

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Oh, please. Don't tell that to an Aggie.

You'll need this pistol grip adapter:

ETA: Link was possibly tracking folks who clicked on it, so I removed it.

Do we still get to use zip ties up front?

ETA: Looks like the 1st link got broken. Let's see if this works. I dunno what this rover.ebay crap is, so I'm making the links cold. Oh, you little fucker - it made it hot & put rover.ebay back in. Making it cold AND breaking the little bastard. You'll have to take out the space to fix the link, sorry.

This should work:

I am unable to recommend these nitwits unreservedly after they shipped two separate gift jigs to one recipient and repeatedly claimed to eBay that they had shipped to both recipients. They make a very nice jig - if you can get it. I don't recommend confusing them with multiple addresses.

This comes w/ the pistol grip adapter above.

Posted: 2/9/2017 10:14:49 PM EDT

[#36]

Yep, that one should work.

Posted: 2/10/2017 1:49:09 AM EDT

[#37]

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You can make whatever you want.

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Quoted:
You can make whatever you want.

Yeah, I know, my house is filled with cast plastic lowers à la Boris.*

I was only addressing backbencher's comment that it would not be a firearm before it was assembled or after it was disassembled again. I'm fairly sure that if the ATF noticed it had ever been assembled, one of their lawyers would come up with some exotic criteria to prove one or another part to be the legal receiver. Which isn't a problem for most purposes but perhaps is for some (travel through certain states, on certain Federal properties, etc.).

* ETA: I don't mean to imply that my cast lowers look or meet specs nearly as well as Boris', because so far they don't, but the principle is sound, and I've lost track of how many test castings I've made, presumably all of them being legally receivers, even when they don't fit or work quite right.

Quoted:
I don't have a $700 5.7 AR upper, so once I get my hands on a trigger jig, I'll give this a shot - a single shot, that is - w/ the 7.62x39mm upper sample gave me. Unless he wants me to try it w/ the upper I gave him.

Great heavens, man, why wouldn't you first try it with the .22 upper? Just remind me to get it to you one of these weeks.

Posted: 2/10/2017 10:10:04 AM EDT

[#38]

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Quoted: Great heavens, man, why wouldn't you first try it with the .22 upper? Just remind me to get it to you one of these weeks.

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Oh - had forgotten about it. That won't really test the buffer tube, however. I thought you were going to tell me to go big or go home.

PappaSunrise on Weaponeer has suggested hose clamps instead of zip ties. A bit sturdier.

Posted: 2/10/2017 10:25:57 AM EDT

[#39]

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Quoted:

Not just a zip tie. The rear lug of the upper will have to fit in the rear slot of the trigger jig. If it's not wide enough, we'll have to widen it; if it's too wide, we can add shims - and maybe some bubblegum?

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You need to keep it lined up on all planes, not just horizontal. Even just having a rear pin isn't a great idea, but it's better than no pins at all.

With just zip ties, or even hose clamps, every time the hammer strikes the firing pin it's going to push the entire upper forward. Any pressure on the upper, from holding the handguard or resting it on sandbags or a pack, etc. is going to push it out of alignment. Every time it recoils, it's going to get interesting.

And it's time to give up on superglue, it doesn't belong anywhere near a firearm.

Posted: 2/10/2017 12:15:33 PM EDT

[#40]

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Quoted:
You need to keep it lined up on all planes, not just horizontal. Even just having a rear pin isn't a great idea, but it's better than no pins at all.

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2 hose clamps should do it. Or 3 for added assurance.

I'm still curious how you plan on keeping the buffer tube straight. I wouldn't trust the stock to keep it dead nuts for the epoxy.

Have a tig welder?

Posted: 2/10/2017 1:51:07 PM EDT

[#41]

Quote History

Quoted:

2 hose clamps should do it. Or 3 for added assurance.

I'm still curious how you plan on keeping the buffer tube straight. I wouldn't trust the stock to keep it dead nuts for the epoxy.

Have a tig welder?

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Quoted:

Quoted: You need to keep it lined up on all planes, not just horizontal. Even just having a rear pin isn't a great idea, but it's better than no pins at all.

2 hose clamps should do it. Or 3 for added assurance.

I'm still curious how you plan on keeping the buffer tube straight. I wouldn't trust the stock to keep it dead nuts for the epoxy.

Have a tig welder?

Nope. We'll try it w/ the .22" LR upper 1st, then the 7.62x39 upper. The first test will just be of the hammer alignment. The second test will be how well we aligned the buffer tube.

Apparently, the Hera stock will take both mil-spec and commercial diameter tubes. I have both, so we'll see which one fits best. If epoxy proves necessary, I'll try that. If I get to the epoxy, I could use an actual lower & upper, and a 1" dia wood rod to align the buffer tube before the epoxy sets.

Josh, I'm well aware the bolt carrier recoils into the buffer tube, so yes, it has to be closely aligned to perfect. That was the issue Orion's Hammer had w/ the Pine A.B.O.R.T.I.O.N. - his front pin boss had broken off from the wooden lower, so only the rear pin was holding the upper in place. He wasn't using zip ties, however. He did have his buffer tube wired in place, however, after his buffer tower boss broke.

Posted: 2/10/2017 2:03:58 PM EDT

[#42]

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Quoted:
Oh - had forgotten about it. That won't really test the buffer tube, however.

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Quoted:
Oh - had forgotten about it. That won't really test the buffer tube, however.

Best to start small and simple in case it turns out to be an especially bad idea.

Quoted:
PappaSunrise on Weaponeer has suggested hose clamps instead of zip ties. A bit sturdier.

That was going to be my suggestion too.

Quoted:
With just zip ties, or even hose clamps, every time the hammer strikes the firing pin it's going to push the entire upper forward. Any pressure on the upper, from holding the handguard or resting it on sandbags or a pack, etc. is going to push it out of alignment. Every time it recoils, it's going to get interesting.

The rear takedown pin should locate the upper to the trigger jig longitudinally and should locate the rear of the upper vertically. If needed, a shim at the front of the jig (where the rubber stop is now) could correct the vertical location if it the upper receiver were too low in the front. If the upper were too high in the front, a file should be able to fine tune it.

Horizontal location of the front of the receiver is going to the the harder bit. Best low-tech solution thing I can think of off the top of my head is to clamp a block onto the front of the jig and slot and drill it to take the front takedown pin. For the lazy or drill-less, the block could instead be thinned down at the front to the width of the front takedown stud and clamped again. Not a lot of meat on that stud for a clamp to grab onto though.

Quoted:
And it's time to give up on superglue, it doesn't belong anywhere near a firearm.

Quoted for truth.

Posted: 2/10/2017 5:01:18 PM EDT

[#43]

Quote History

Quoted: The rear takedown pin should locate the upper to the trigger jig longitudinally and should locate the rear of the upper vertically. If needed, a shim at the front of the jig (where the rubber stop is now) could correct the vertical location if it the upper receiver were too low in the front. If the upper were too high in the front, a file should be able to fine tune it.

Horizontal location of the front of the receiver is going to the the harder bit. Best low-tech solution thing I can think of off the top of my head is to clamp a block onto the front of the jig and slot and drill it to take the front takedown pin. For the lazy or drill-less, the block could instead be thinned down at the front to the width of the front takedown stud and clamped again. Not a lot of meat on that stud for a clamp to grab onto though.

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Keep in mind the AR 5.7 upper ejects downwards, through our non-existent magwell. If you're reaching the forward takedown pin, you've basically recreated the magwell - which I'm hardly opposed to, as then we can use any upper. I note that MGI's interchangeable magwells run $275 a pop - it's cheaper to cut up an existing AR lower than use their parts: http://www.mgi-military.com/store/index.php?product_id=26

If we used longer pins in the trigger and hammer, we could use bits from the Flat Spot - bolt the side plates onto the trigger jig. Attaching the magwell plates, which would give us the forward takedown pin boss, would require some attachment method, and for once I agree w/ you cats, superglue doesn't work on the Flat Spot lower, b/c I've tried it. Welding and brazing works - but then you might as well weld up the whole thing. Screwing it together might work, as well as riveting. I have not tried two-part epoxy for that, so that remains a possibility.

Posted: 2/10/2017 7:21:08 PM EDT

[#44]

^^^

Won't that defeat the purpose of using parts that cannot be determined firearm status by themselves?

Would not easily be disassembled that way, but in theory should work.

Posted: 2/10/2017 10:08:33 PM EDT

[#45]

I think that none of the parts being a firearm by itself is a possible advantage of this - but it's not the defining advantage. I'd like a no mill, no weld, no 3-D print method of making a capable firearm - this would appear to be one such way. If I have to Dremel off the end of a trigger jig, or epoxy a buffer tube into a stock, I think that's easily done work that can be done by the average apartment-dweller. I'd prefer to not have to drill precisely-located holes - if we go that route, an 80% lower becomes the obvious answer.