fly weight breakdown skeleton single shot pack rifle?

[Big Chudungus]

OP, ya know, you could just buy a Kel-Tec SU-16, and you'll already have most of what you're asking for, in a semi-auto. Just saying.

Sent from my moto x4 using Tapatalk

On one hand its "close" but still about 2x the weight I'm aiming for, and 2.5lbs is like a whole other sleeping bag of diff between 2 man or 4 man tent for hard core backpackers.

Its also about 4x the volume, and very awkward shape even with packed.

I'm also wanting to give people ability to use the fairly wide variety of rounds now used in AR-15 and AR-10 platforms, as well as choice of barrel specs.

On one hand it will be basic universal kit, but on the other its perfect for the guy that wants to use a specific barrel and round for particular shot.

[Big Chudungus]

Originally Posted by sbo80 View Post
Neither. You submit a sample/design to the ATF and ask them "is this a gun?" If the answer is no, you can call it an "80%" and sell it without gun rules. That's really as simple as it is. The percent thing is made-up marketing.

And you can pretty much forget about getting any such letter in the near future.

Are you saying they will call everything and anything "a gun" or that paperwork will be snail-walked for next few decades and never leave the ATF's in-box.

[ar15barrels]

On one hand its "close" but still about 2x the weight I'm aiming for, and 2.5lbs is like a whole other sleeping bag of diff between 2 man or 4 man tent for hard core backpackers.

Its also about 4x the volume, and very awkward shape even with packed.

I'm also wanting to give people ability to use the fairly wide variety of rounds now used in AR-15 and AR-10 platforms, as well as choice of barrel specs.

Your strict requirements and lack of compromise make a solution unreachable.

[LynnJr]

An AR15 barrel is held in with a threaded collar nut, it's just a larger version of the AR7 nut.
The collar nut simply holds the barrel in place, chamber pressure is contained by the barrel.

If a bolt and wing nut combo is used, and if the bolt shank is of the correct diameter, it won't make any difference to the gun.

Now you've done it. You posted the only difference between a hingepin and a bolt and wingnut is the bolt and wingnut look less appealing but are functionally the same thing.
If Pacrat reads that he might cry?
The only reason for the press fit is so the pin doesn't fall out on it's own.
Let's see if we taught an old dog a new trick?

[LynnJr]

Big Chudungus
Look at the Mark Serbu RN50 50BMG and see if that helps.
It is basically a screw action like they use when sending lines ship to ship and has zero headspacing ever as you just tighten up the screw tighter.
Mark is also a manufacturer and you could probably write him an email and see what he has to say.

[G-forceJunkie]

So we have gone from 17" long (post #9) to 28". Make up you mind.

. 20" barrel and another 8" of stuff for a 28" packed unit would be A-OK if it packs into slender straight shape.

[G-forceJunkie]

If I was to scratch build what I think the OP wants, i would use a pencil weight barrel, thread the end for a cap/spring loaded firing pin like the Serbu 50 cal you mention and tig weld on mounts for a tubular "stock". Maybe try and use off the shelf prethreaded savage barrels or something. I would probably design the cap to be the entire firing mechanism, pull the pin back till it locks on a sear and can be released by a simple one lever mechinism pushed with your thumb. It would look like a giant Sten gun without the trigger assembly.

Big Chudungus
Look at the Mark Serbu RN50 50BMG and see if that helps.
It is basically a screw action like they use when sending lines ship to ship and has zero headspacing ever as you just tighten up the screw tighter.
Mark is also a manufacturer and you could probably write him an email and see what he has to say.

[Big Chudungus]

So we have gone from 17" long (post #9) to 28". Make up you mind.

Now that you mention it, since this would certainly be a nation wide if not world wide product, figure the whole range of AR barrel lengths is on offer from 10"(with SBR stamp where required) to 24".

While the 16" barrel (17" package) seems most popular and sensible, I'm expecting good demand for 12.5" barrel and about 13.5" package mostly because about 13.5" is about right for stock frame. "Package" might be 1", 2" or more than barrel, depending on what happens and how much field assembly is the sweet spot.

Since its single shot it really opens up options for reloaders for lower that normal power.

I'm thinking a 9mm (or 10mm) 12.5"(or shorter) AR barrelled unit would be popular. Ultra Fly Weight, cheap ammo but still real rifle ergonomics for good accuracy, strapping filled canteens to stock for weight not really needed.

[Big Chudungus]

Big Chudungus
Look at the Mark Serbu RN50 50BMG and see if that helps.
It is basically a screw action like they use when sending lines ship to ship and has zero headspacing ever as you just tighten up the screw tighter.
Mark is also a manufacturer and you could probably write him an email and see what he has to say.

That thing that blew up? Yeah, I was kinda thinking of that but now I'm leaning on towards a cheesy actual bolt action and cheesy receiver as outlined in prior posts and no real reason why couldn't feed off an actual mag with just a tad more engineering. Don't worry, I'm keeping close watch on Mission Creep and Weight Gain, and still accepting extra fiddling if needed.

It seems all the strength of an AR action is in the barrel, barrel extension, and region of bolt with the locking lugs, and a very light weight low spec, low precision bolt action receiver could make it feed off a mag pretty much like a normal bolt action, just not as wonderfully authoritative and impressive feeling to operate.

[LynnJr]

On a bolt action receiver the lug abutments and the actual lugs on the bolt do all the work. The rest of the bolt is just there to turn the locking lugs which are the only piece of good steel.
The problem with a bolt action is length but if you limit the cartridge selection to pistol rounds you can shorten the action.

[pacrat]

[1] ... An AR15 barrel is held in with a threaded collar nut, it's just a larger version of the AR7 nut.
[2] ... The collar nut simply holds the barrel in place, [3] ... chamber pressure is contained by the barrel.

[4] ... If a bolt and wing nut combo is used, and if the bolt shank is of the correct diameter, it won't make any difference to the gun.

[1] ... Correct yet incomplete, because fails to take into consideration the basic applied physics inherent in the 2 different designs.

The 7 is a simple blowback action. Majority of the miniscule force generated by 22rf pressure, takes path of least resistance. Forcing the bolt rearward to cycle action. Very little forward force is applied to the barrel or its connection to receiver. That is accomplished on the Ruger 10-22 with 2 small screws under barrel connection.

The 15 is a rotary locked breech. Unlike a standard bolt gun. The bolt is locked into the barrel itself at ignition. Creating a sealed pressure vessel. With a hole in the front. So [equal but opposite thing] majority of applied force at ignition is directed rearward. With a smaller amount of the contained pressure acting internally against the case shoulder, trying to force barrel forward.

Typical CF bolt gun is 3 piece design. Bolt lugs abut receiver, barrel screws into receiver. Again majority of force is directed to rear. But enough remains to force barrel forward if not a tight threaded fit to receiver.

Saw first hand a guy POP a barrel off a small ring mauser. [sloppy threads]

[2] ... Yes. But must meet criteria for the design parameters..

[3] ... True in all designs. Even muzzle loaders. Pressure and Force are relative to one another. But intrinsically different from each other. That's why I underlined them above.

More pressure can create more force. But Pressure is equilateral, it pushes in all directions equally. Whereas applied Force is Linear. Newton's second. If static, it is pressure. If the pressure is moving something, [bullet] forward, or [gun] back, it is a measured force. It goes from PSI to Foot pounds as measured energy applied.

[4] ... "CORRECT DIAMETER" for H&R top breaks. IS A PRESS FIT. THAT'S WHY THEY MAKE THEM THAT WAY. Because the barrel CAMS against the pin to force the breech face tight to the frame. For a solid lockup.

Sloppy pin = sloppy lockup = sloppy accuracy

So what's the point of taking a gun that doesn't fit any of the criteria the OP was looking for. To heavy ... To spendy ... Can't fold.

And make it worse?

[LynnJr]

4] ... "CORRECT DIAMETER" for H&R top breaks. IS A PRESS FIT. THAT'S WHY THEY MAKE THEM THAT WAY. Because the barrel CAMS against the pin to force the breech face tight to the frame. For a solid lockup.

It's like talking to a wall but I am very patient.
The press fit is only to keep the pin from falling out in the field. it can have a nut on both sides to retain it but the press fit is the cheapest way to go.

[smittty]

So we have gone from 17" long (post #9) to 28". Make up you mind.

I would want shortest length that meets legal definite of "rifle".

[Big Chudungus]

I would want shortest length that meets legal definite of "rifle".

26"? That would mean either a 10" barrel or bullpup trigger. But would a bullpup trigger be that bad in a single shot or crude bolt action if an extra trigger cocking step is used?

I'd been thinking OAL not a factor for assembled rifle, and more length better and was looking at tip of the barrel AR sights to max iron site radius, and OAL when broken down the least important to minimize dimension (including the dimension of weight).

I guess it might be possible to design a crude bolt action that screws onto AR's barrel extension, then the skeleton frame clamps to the barrel anywhere along its length, then you buy a stick of 1/4" aluminum tube off Ebay pre-cut to your choice of 1" gradients to make your custom length bolt-action bullpup.

24" 308 barrel with another 8" of bolt action on the back and another 10" of silencer can on the front for 42" unit where the back 20" is projecting over your shoulder and it has a comfy neutral balance, maybe even some negative balance so the upward force of the grips will keep your arms from getting tired when scoping a target for several minutes? Sure, why not. "Negative Balance" as cure for arm strain???

[pacrat]

YES he said this.

The press fit is only to keep the pin from falling out in the field.

^^^^^ THE "EGG-SPURT" has spoken. Loose barrel to receiver fit, has no detrimental accuracy implicatons.

By that tortured reasoning. Loose is the NEW TIGHT.