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Old May 3, 2012, 10:19 AM   #1
jason41987
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technical discussion for the function and design of self-loading rifles

hey everyone.. im just making this thread for myself, and people looking to debate the various aspects of a self-loading rifle... different types of actions (blowback, recoil, gas), different materials, construction methods, calibers, etc....

i would like to know what you would think of as the perfect semi automatic, if in your own image you were able to design one?..


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first off, i would like to know other peoples opinions and feelings about gas operated (long and short gas piston systems), recoil operation (long, like a browning auto 5, and short like a johnson 41, or handgun) as well as blowback, standard blowback, and the various delay mechanisms such as roller, and lever delayed... and for gas and recoil operated systems, what type of locking mechanism do you like most (rotating bolt, tilting bolt, etc)

what do you think would be the best operation in your opinions and why?

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i would also like to know what type of feeding mechanism you think is best.. box magazine, internal or external... helical, rotary, belt, as well as what magazines of already existing rifles you like most?.. ar-15 mags, AK mags, etc..

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im also curious what you guys think about one piece furniture such as those used on the garand, M1A, mini-14, and SKS, vs the seperation of forearm, grip, and stock such as those on the AR-15, AK, FAL, ect

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i would also like to know how you feel about the different calibers available... if you prefer lighter, more plentiful ammunition, such as 5.56 or 7.62x39, or if you believe the added range and stopping power of a .308 to get more done with fewer rounds is the better way to go?

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and lastly, if anyone else could think of any other features or ideas, feel free to discusss them

**********************************************************

Last edited by Brian Pfleuger; May 3, 2012 at 07:47 PM. Reason: Clean Up
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Old May 3, 2012, 10:26 AM   #2
kraigwy
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There is no "perfect" system, what works in one gun wont work in another.

Imagene the recoil action of a 1911 in a Garand or a piston on a 1911. That's just for starters.

Hatcher's Notebook gives a pretty good detail of different systems in different guns. Studying that, you get the ideal that one system will not work in all guns.
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Old May 3, 2012, 10:35 AM   #3
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Whadda' ya trying to do, ruin the gun maker economy, or something?
If there was one perfect design, where's the motivation to keep buying stuff?
You'd put the gun makers out of business, the safe makers, the ammo makers.
Well, you get the idea.
Positively un-American, that's what it is.
Geeze, the noive of some guys.
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Old May 3, 2012, 10:45 AM   #4
jason41987
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of course theres a perfect design.. but that perfect design is different for everyone.. every feature has its tradeoffs... but in the eyes of every individual theres the perfect balance of these tradeoffs... so i would like to know what tradeoffs you think are the best ones to make, and why?... as well as maybe discuss some other ideas you may be having..

on the other forum, people were discussing the different ways of gas blowback, and gas operated designs, some you typically dont even see (like gas-delayed blowback systems)..

i myself have been working on a design in 3D that was lever-delayed blowback, and one that had a floating chamber that acts sort of like a short-stroke gas piston that moves about 1/10th of an inch to unlock (by rotating) and send the bolt flying backwards

anyway... these tradeoffs will always exist, and someone will find one group of features to be better (in their opinion).. so there will always be plenty of interesting combinations of features for us to choose from
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Old May 3, 2012, 12:09 PM   #5
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jason41987, to prevent this thread from being closed, I suggest that you ask a mod to move the thread to the semi-auto rifle forum.
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Old May 3, 2012, 06:57 PM   #6
jason41987
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why?.. though the title specifies self-loading... people are free to discuss their ideas for any type of rifle or pistol action.. i have no problem with it
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Old May 3, 2012, 07:10 PM   #7
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I would really like to see someone do a Koksharov "balanced recoil" action on an AR-15 or M-16, as the Russians did with the AEK-971; in this, the gas impulse simultaneously forces the bolt carrier rearwards and a slightly heavier counterweight geared to the carrier FORWARDS, so the rearward impulse (recoil and bolt carrier) is balanced out by the forward impulse of the counterweight. The result is an essentially recoilless rifle, and you can see an example being fired at http://www.youtube.com/watch?v=gOozMdEV_AU
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Old May 3, 2012, 07:32 PM   #8
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SDC.. ive actually already designed one of those from scratch.. i had a gas tube and the gas entered the center of the tube pushing the bolt carrier rearward and a counterweight forward... i was inspired by the russian AEK
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Old May 3, 2012, 08:36 PM   #9
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"...people are free to discuss their ideas for any type of rifle or pistol action."

True. In the appropriate forum. So, self-loaders aka semi-automatics belong here.
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Old May 3, 2012, 10:30 PM   #10
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well, i dont mind if someone goes off topic and has an idea of another type.. it just seemed semi automatics have the most variety
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Old May 4, 2012, 07:20 AM   #11
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"SDC.. ive actually already designed one of those from scratch.. i had a gas tube and the gas entered the center of the tube pushing the bolt carrier rearward and a counterweight forward... i was inspired by the russian AEK"

Did you get it built, or did it stay on paper? Also, in your version, was the bolt carrier geared to travel the same distance and speed as the counterweight, or were both parts operating independently?
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Old May 4, 2012, 11:40 AM   #12
Crow Hunter
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Mine in red, all answers based on use in a semi-auto rifle. Other uses would change my choices.

Quote:
first off, i would like to know other peoples opinions and feelings about gas operated (long and short gas piston systems), recoil operation (long, like a browning auto 5, and short like a johnson 41, or handgun) as well as blowback, standard blowback, and the various delay mechanisms such as roller, and lever delayed... and for gas and recoil operated systems, what type of locking mechanism do you like most (rotating bolt, tilting bolt, etc)

what do you think would be the best operation in your opinions and why?

In my opinion the short stroke piston has the best attributes for a semi-automatic rifle. Assuming the rifle is designed adequately to support it. (Not a piston stuck in an non-piston rifle) The short stroke piston isolates the operating system from the rest of the rifle, this helps reduce fouling, allows variation of barrel length/weapon weight, easy accommodation of suppressor back pressure, allows for Over the Beach vent holes, could allow for accommodation of gas erosion on vent holes on barrels with replaceable bushings.

Rotating multi-lug bolts with appropriate radiusing/chamfering to reduce stress risers. The mult-lug rotating bolt gives greater accuracy due to more repeatable engagement and potentially better accomodation of fouling if designed correctly.

---

i would also like to know what type of feeding mechanism you think is best.. box magazine, internal or external... helical, rotary, belt, as well as what magazines of already existing rifles you like most?.. ar-15 mags, AK mags, etc..

External, properly designed polymer magazine with steel inserts for feed lips. Option #2 is aluminum mags similar to the AR. Steel is on the bottom of the list.

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im also curious what you guys think about one piece furniture such as those used on the garand, M1A, mini-14, and SKS, vs the seperation of forearm, grip, and stock such as those on the AR-15, AK, FAL, ect

Separate.

---

i would also like to know how you feel about the different calibers available... if you prefer lighter, more plentiful ammunition, such as 5.56 or 7.62x39, or if you believe the added range and stopping power of a .308 to get more done with fewer rounds is the better way to go?

Depends on use, assuming general issue combat, 5.56 type rounds. (5.45/5.8/5.56)

---

and lastly, if anyone else could think of any other features or ideas, feel free to discusss them

Must have modular components. Ability to remove and replace components without heavy tools. Lighter weight components. Aluminum/polymer wherever possible. All operating controls (Safety, mag release, trigger, bolt hold open/release) available to the dominant hand (right or left) leaving the off hand free to facilitate mag changes, scratch nose, etc. Ability to charge the rifle with the offhand without disturbing the sight picture. Designed so that it is impossible for the firing pin to fall without the bolt being fully locked into battery. NO BULLPUPS!
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Old May 4, 2012, 02:12 PM   #13
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I think there are several semi-automatic rifles that are perfect. However, that is not saying any particular one of them "best."

Of the old ones, I like the FN-1949 the best, maybe even more than an M-14 but neither one has been made for decades. An M1-A is not an M-14.
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Old May 4, 2012, 04:34 PM   #14
jason41987
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i like the fact that on an M14, SKS, mini-14, etc the stock can be removed, and the actual operating system itself is very minimal... theres not much to them, and once you take off one stock and add another you can dynamically change the platform...

SDC, the system i designeds not on paper, no prototype either.. but i did design it in 3D.. the carrier and piston moved independantly from eachother though.. i didnt have them geared together...

were you suggesting a rifle where the gas system just pushes back on either the bolt carrier or the counterweight, and then gears or some mechanism throws the opposite component in the opposite direction proportionally?
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Old May 4, 2012, 05:06 PM   #15
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I have a new unique rifle gas operating system design in mind, but can't find a way to build/market it.
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Old May 4, 2012, 06:00 PM   #16
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"were you suggesting a rifle where the gas system just pushes back on either the bolt carrier or the counterweight, and then gears or some mechanism throws the opposite component in the opposite direction proportionally?"

In Koksharov's design, the two moving halves of the system are geared together through a gear wheel in the centre, ensuring that neither half can move any further/faster than the other. The AK-108 is also using this design, with everything placed in an elongated gas tube above the barrel.
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Old May 4, 2012, 06:29 PM   #17
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amrecon, you should try building it in a 3D environment first, to make sure all parts match up and work properly, and then possibly run heat and pressure similations on the parts

SDC, when you say geared together with a wheel in the middle.. it sounds like in the gas tube is a spur gear... attached to the bolt carrer and the opposing counterweight would be rack gears... the gasses can either act on one or the other, both, or you could have the gas system work on the spur gear similar to how a tubrocharger works...

easiest was would be to have the gasses press on the counterweight, when the counterweight reaches its full limit the gasses vent, pressure drops, and the spring behind the counterweight throws the counterweight forward, which also closes the action... anyway, thats how i would do it, i dont know how the AEK-971 does it
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Old May 4, 2012, 09:23 PM   #18
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In the AEK, the tungsten counterweight is on the forward end of a tube that the piston arm extends into, and that whole assembly fits inside what would be the regular gas tube; when the gas impluse drives the bolt carrier rearward, that also requires the counterweight to move forward by an equal amount (half of the gear runs in a track on the inside of the counterweight tube, and the other half of the gear runs in a track on the piston arm). It's easier to visualize if you just imagine the gear spinning in one spot, with the counterweight running forward as the bolt carrier runs rearward, each with a slotted track engaging that gear.
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Old May 5, 2012, 12:51 AM   #19
jason41987
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sounds like a rack and pinnion set up.. like the steering in your car... as the regular, common spur gear in the middle spins, it moves a long toothed bar called the rack... it would be pretty simple to design something like this.. even for the AR-15/M-16 design if you had a suitable way for dealing with the bolt tilt present in the design when converted to a piston...

since the AR-15 is direct impinged, all moving weight is inline with the shoulder so you feel very, very little recoil as it is... gives the M4 and AEK a similar controllable rate of fire... since what youre really doing is just negating the forces of the bolt carrier flying back, in an AK with a long stroke piston theres a lot more weight there.. very little in an AR...

since the barrels fixed on both you still have to deal with the recoil itself of the round pushing forward and the rifle itself, from the barrel pushes back... so the AEK still has recoil
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Old May 5, 2012, 07:33 AM   #20
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But with the AEK design, you can balance both halves of the rearward and forward equation, leaving a rifle that is essentially recoilless; on one side you have the bolt, bolt carrier, projectile, gas and other ejecta, and on the other, you'd just need to adjust the weight of the tungsten counterweight to balance those out.
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Old May 5, 2012, 10:08 AM   #21
jason41987
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i just dont see how it could balance out the initial recoil that pushes the entire firearm back before any gasses reach this device to cycle it
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Old May 5, 2012, 10:13 AM   #22
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actually, i just did some more reading on the AEK... it doesnt stop the recoil itself, just balances the impact and inertia of the parts inside
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