You are a bright person Longziz!  
i would most certainly buy this if you get it produced.
Keep us informed

wonder what the price might be?

very cool, longziz! as a lefty i am quite excited at the hopes of this prototype becoming a reality

The AR style of mag well is troublesome for the bullpup layout...it's fine for slow mag changes in static positions, but in motion and at odd angles the .90degree angle is tough...it pushes up at the buttstock and can be a bit of a fight....what needs to happen is an insert that pushes back and locks up...which will keep the buttstock closer to a firing position........this is huge...it's the one area that kills the bullpup for a lot of AR users.     The next is the mag release ,bolt release and safety controls.    Biggest problem is simplicity .....the more ergonomic the design the more complex it becomes.

Glad to hear he's walked you through it all!  I sent an email (not a PM) to you.

Longziz, would this design work with a full-auto lower?

Good question. At this moment, no, because I never had an auto one. In the future, maybe. I am thinking to design a completely lower of my own, but this will walk away from AR platform. I don't know if this is what folks want or not.

It would have to have a sear trip linkage similar to the auto version of the ZM LR-300 (Para TTR) since there is no bolt tail to trip the sear like with a standard AR.

I would rather have a lower that accepted AR mags, perhaps had SOME cross-compatibility with AR parts, BUT that had AR controls IN THE SAME LOCATIONS as current... especially the trigger-finger mag release - preferrably Ambi.

I would be even MORE interested in a Bullpup lower / shell that could use existing AR uppers and barrels - even if they required a different bolt carrier assembly to accomplish.

Very nice design Sir

You mean a bullpup that has no ambi ejection feature? If you need ambi ejection, then the existing AR upper has to be changed. It is possible to use existing piston system though. I am using an AR barrel with small modifications.

I suspect if you could accomplish that, many folks would be more than willing to give up ambi-ejection.  If you could keep the bolt (not the carrier) those who wanted to switch ejection sides (lefties) would or could get Stag left upper assemblies.  

~Augee

My Steyr AUG A1 16" carbine with factory NATO mag conversion stock for NATO/ M16/ AR-15 mags

Congrats on your project progress so far and hoping that you have success with it when your work is completed.

I would just like to add some of my opinions about the bullpup design, I had mine since 1989 and just converted it to accept NATO M-16 mags with the stock conversion in 2005.

First +1 no thumbhole stock, it would interfere with mag reloading in my opinion.

On my picture the mag release button is the rear circle metal detail on the side of the magwell, I would prefer that mag release button to be vertically longer with a rounded upper and lower ends, also protected by a protruding fence, mine also have a lower mag release (at rear of the magwell) which is nice because I could hit it with my fresh mag before reloading.

If possible there should also be a right side mag release when using the rifle on the support side (that would be my left, I'm a right hand shooter).

I like my AUG but it is lacking with these noted desired features and also would like to have a modular rail system which allows the user to add small picatinny rails at the sides and bottom rails.

Another conventional non bullpup design you should look at is similar with the FN SCAR, Bushmaster ACR and  Beretta ARX-160.

I like the switchable ejection feature of the Beretta ARX-160, take a look at this AR15.com SHOT Show 2011 vid.


http://www.youtube.com/watch?NR=1&feature=endscreen&v=6YS8eAiDUzs

When I started this project, I didn't know about ARX-160, I didn't aware its existence until early this year, around April or May. When I first learned it, I almost want to quite mine, because I think it changes sides one less action needed than mine. However, after close look at its patent and videos online, I do have some question about how well it would hold in combat field.

My first question is, why don't they make a bullpup design out of it bolt design? They have all the ambi feature you can imagine. The only downside might be the reciprocating charging handle.

If what I understand is correct from the video, they change ejection direction by pull a button which is recess into the upper receiver. I looked at their patent, their method of changing direction is throw two identical extractor/ejector. There is a plate at the back of the receiver which has a hold on it. The extractor/ejector have very long tail. if the hole is lined up with one of the extractor/ejector, that part turns into extractor, and the one is blocked becomes a ejector. So switching side is just disposition the plate with that hole.

Now, not to bash ARX, I think there are some drawback of this design. First, as it shows, the switch button is recessed. This is for a good reason. If it is exposed, then there is a chance it might be pushed unintentionally. The design of this button is that it has to be pushed all the way to the other end. Otherwise, the hole might line up with nobody, then both extractor/ejector turns into ejector. The spend casing will either left on the bolt or fall into the receiver to cause double feed. Now, since it is recessed, you need some tool to reach inside to push the button. Well, we could argue that by using a fresh cartridge can do the job, but in the battle field, will you always keep a round or a tool in your hand? If it is attached to the rifle or sling, you still need time to reach it and then use it. With that in mind, I found that my design, although need two actions to actuate, might in the end be done quicker. However, since my rifle currently have some friction issue, I am yet to demonstrate the one hand operation as I envisioned, so it is too soon to tell.

Secondly, the AR15 bolt orientation has seven lug to lock with the barrel extension. if I remember correctly, the ARX also has seven (3 up, 4 down), but the two extractor/ejector occupied twice has much space as AR15 bolt extractor does. Although AR15's ejector hole would weaken the correspondent lug, I considered the AR bolt is stronger than that of the ARX. However, I don't have data to prove that, just a hunch.

Overall, I think ARX-160 is great rifle, maybe a little bit over engineered. Let's see how it performs.

God that thing looks bulky!

Ambi ejection is what makes this useful.  There are already bullpups in the market –– this one is useful for the 20% or so of us who shoot left-handed.

To work in a full auto lower, the stock might have to be lengthened a little to allow for a longer carrier.  Compare a full auto carrier and a semi-auto carrier sometime and you'll see what I mean.  The carrier would need to be long enough to allow for a sear trip to be present.  It certainly would make the system a lot more attractive to those with M16s, and would probably be necessary if you ever wanted to try to sell to military/law enforcement.

Designing a completely new lower would be cool, but would also increase your regulatory burdens in the US exponentially, as it would then be a firearm instead of a firearm accessory.  Personally, I'd rather see a kit that can accept an M16 lower, and of course semi-auto AR lowers as well.

Putting any effort or changing any design to allow full auto lowers would be a waste of time in my opinion, it's not a large enough market. Also I believe that the fact that this uses an ar lower is a fantastic idea in that it will allow you to avoid the red tape of manufacturing a firearm altogether which will increase your profitability and chances of getting this off of the ground and into the market.

This is a tag to follow your progress. I am absolutely floored, Longziz. Keep up the great work!

Really incredible, and inspiring. I wish you the best of luck, and WHEN (not if) you reach the commercial level have one ready for me.

I know I am biased, but I think the percentage should be higher. Even for a right hand person, I think this rifle will help in CQB or rat hunt situation. It allows you to shoot from the weak position under some kind of cover, a street corner for example.

very interesting concept. keep at it and keep us posted.

mistake

Amazing, really is, I hope this makes it to the market one day.

Don't ever give up.  We could be looking at a future Ronnie Barret.  He went through the same setbacks etc.

MIllions of users in military and law enforcement would probably disagree.  Granted, not all of them would buy such an accessory, but it might make sense to keep it compatible from the start and cater to both the civilian semi market and the civilian/military/LE full auto market from the get-go.  I'm excited for such a product, but as I don't own a semi AR, I wouldn't have much use for it without a happy switch.

I don't necessary disagree with you. The method I demonstrate on the video is not what I envisioned. The correct method I will achieved is using only one hand to latch and turn. It is not just possible, it will be done. Since changing shoulder also need time, doing it and change ejection direction can be done at the same time, if trained properly. However, I do admit that on this regard, FN2000 beat me to it. I can imagine in a room to room rat hunt operation, constantly changing side is distracting. However, this is more or less a special op kind of mission and judging by the fact many country has ordered this rifle for special op, I can bow to FN2000with respect. I don't know the exact reason why no army had adopt this rifle yet, I think it might related to the front ejection concept. Who knows.

If the bolt carrier length is the point of concern there then I can tell you that this is not a problem. I have seen full auto LR300 bolt carrier on paper, it is only a little bit longer than mine. The shortened "buffer" tube you see in the picture actually have more than enough room to accommodate a longer carrier. The thing I am not so sure at this moment is the switch.

Would change the auto sear into another design involve a reapplication of license?

If it's a registered receiver, no.
If it's a DIAS, it would be very hard to do without a re-design, which would be making a new machine gun...

If he's going after military contracts then he has to compete with some really big boys. I think most LE use semi as it is, I could be wrong. Also how many LE agencies use bull pups in the US? I think a simple solution for you would be to get a semi AR.

It is not easy to have a auto Bullpup in an AR platform. The auto sear of M16 has a 180 degree operation turns of the lever. It is not possible to achieve that with a simple 4 bar mechanism as a Bullpup may have. My personal view is that if aim for military adoption, a new lower receiver would make sense, the lower receiver will have less part, the trigger pull, switch, and mag release can be optimized with no constrain. It would request more research and development investment, and the outcome is uncertain. It will make no sence if the army is not asking for one. However, if the opposite is true, then civilian market would demand the same, less the auto sear part. So I think it would be a safe choice to stick with the AR lower shell approach at this moment.

From what I understand, the full-auto version of the LR300 moves the sear pin location.  IE not a good starting point, since the lower would need to be modified if you went with that setup.


I don't think something like this would get millions of LE orders or anything, but you could probably find departments who would buy some to play with.  If you actually want to target millions of LE/military sales, I think the odds are heavily against you regardless of whether you use the AR/M16 lower or make a new lower from scratch.  If you're targeting the purely recreational shooter and if it's possible to keep M16 compatibility without too much additional effort, the benefit is that you'd just have more potential buyers.  I don't know too many M16 owners who would spend $1000 or whatever for a kit that will turn their $16k machine gun into a semi-auto.  But a bunch of them spent thousands of dollars on Shrike uppers.  Speaking of which, when do you start taking deposits?

Wow. This is purely spectacular. As someone who is a Freshman in college going for a ME degree, this is a huge inspiration. You definitely have something good here, and I wish you luck with your endeavor.

What is being done here is outstanding.  I find the support and constructive nature of the comments extremely reassuring of the site.  I am new.  And, I am impressed.  

The right left hand issue is important because I shoot lefty.  I see it as an opportunity and purpose for the rifle.  Keep on with the project.  I will be supportive.

looks friggin awesome

Great that Longziz's invention is arousing so much interest in AR15!

He is indeed a great talent and will be wonderful if somehow we can keep him in the US.  I've known him for few years on artofwar website.  It is fun and education to me to discuss and learn the AR15 design and operation there too.

When he posted the video of his invention on the artofwar website, everyone was overwhelmed.  we all still are guessing how he made it work.  I sincerely hope that his talent in mechanical design as demonstrated not only by his advanced degree work in St Louis but also this achievement all on his own effort and funding, can pay off for him, AND allows us to have a really great new firearm few years down the road.

GO Longziz!

Bye

Thank you sir thats why I did not quote fmf.  

 

Re the bolt carrier, you could make it two pieces (a la the FA .22 kits) where the bolt carrier just hits a trip for the auto sear. BCG goes back far enough to load new round, comes back forward into battery. The FA trip only slides maybe 1/2" of that to hit the trip.

@fmf Troll much? Not cool.

To Longinziz keep up the good work. Looks cool

Not cool Doc.
 

this certainly was uncalled for.





You are either jealous or a Racist or perhaps both






 

Racism is inexcusable, and that comment is both off topic AND RACIST.
 

Hence why we can't have a couple of beers after a long mission downrange anymore.  People just can't be responsible.  





~Augee
 

Thanks guys! One more reason I love this country. It is not heaven, but beats a hell out of other places. My salute to you all, again!

Any details you can share on the Longziz Mk. 2 or 3?

Longziz #2 will come out before Christmas, at least I hope so.

Is it here yet?
Is it here yet?
Is it here yet?


Can't tell I'm interested...

Great work!!!!!