What makes the AK so reliable?

[No Bananas]

From a techincal/engineering perspective, what makes the AK so reliable?

We all know the can and do jam, and break. However, they have a better track record in this regard than most other designs.

My understanding and questions:
-The parts are made of strong heavy metals.
Q: Was the gun designed , or through happenstance, to put less stress on moving parts?

-Magazines, are very strong, heavy, with reliable springs.

-Chamber and caliber design.
Q: Does the sloped cartridge aid in reliability? Does a sloped chamber do the same?

It's my understanding that the barrle and reciver flex during firing, which is one of the reasons the AKs are less accurate than an AR.
Q: If true, does this somehow aid in reliability?

Big ol' gas tube. Compared to the AR gas tube, it feels like you could drive a Smart car in through the AK's gas tube.
Q: If this helps reliability, how?

Q: Are there other engineering aspects of te AK that shine in terms of reliability?

[mkmckinley]

There are plenty on here that know much more about the AK than I do, but I'll take a whack anyway. Basically you have a big, loose, overgassed piston system with a very tapered cartridge and overbuilt bolt/extractor/magazines. This allows the weapon to function with crappier ammo, crappier parts, and less maintenance than an AR. If you use decent ammo, parts, and maintenance with a decent AR the reliability will be about the same as that with a decent AK.

[Misc Ex-Member]

strong, well-designed magazines

lack of small parts

lots of room in the receiver

"overgassed" system

fixed ejector

Remember, a correctly built AK is very robust and reliable. Most AKs in the U.S. are not correctly built.

[pilotguyo540]

In my humble opinion I think the success of the AK can be attributed to its very simple and robust parts and loose tolerances.

The AK does flex when fired. The intro to zombieland has a good slow motion of this. I don't think that affects accuracy because it is a constant.

[TOrrock]

All barrels flex when the weapon is fired.

That's one reason precision rifle barrels are sometimes fluted, and sometimes shorter than you'd expect, because the fluting stiffens the barrel and the shorter barrels flex less.

Has nothing to do with the reliability of the Kalashnikov.

[TOrrock]

Originally Posted by Jay_Cunningham

strong, well-designed magazines

lack of small parts

lots of room in the receiver

"overgassed" system

fixed ejector

Remember, a correctly built AK is very robust and reliable. Most AKs in the U.S. are not correctly built.

^^^

This, as well as the combination of the severe taper of the original 7.62x39mm and 5.45x39mm.

[Canonshooter]

^^^ THIS ^^^

After a range session with both the AR and AK, when doing the cleaning drill I am always struck at the simpler, more rubust - even if somewhat "primitive" - design of the AK. Compared to the AR, there just isn't a whole lot to go wrong in there!

And of course, those Hungarian 20 round AK steel mags are built like tanks compared to any AR magazine.

[TY44934]

Compared to the AR, the AK has a much higher bolt-to-carrier weight ratio. Once the AK carrier gains momentum, it carries a lot more energy to handle any extraction challenges.

Speaking of extractors, compare the AKs to the AR & you will see the AKs is far more robust and covers a larger area of the rim.

The gas piston on a correctly built AK IS installed to flex. This feature ADDS to the reliability of 7.62 AK.

How do I know?

-I had a "gunsmith" (unfamiliar with AKs) replace the Bulgarian-made & installed piston on my SLR-95 with a U.S.-made piston.

-old piston flexed from the factory.

-new piston installed tight as a drum ("I'll FIX that wobble when I install the new piston!" he told me).

That "fix" turned my reliable AK into a jam-o-matic.

[Misc Ex-Member]

Originally Posted by TY44934

Compared to the AR, the AK has a much higher bolt-to-carrier weight ratio. Once the AK carrier gains momentum, it carries a lot more energy to handle any extraction challenges.

Speaking of extractors, compare the AKs to the AR & you will see the AKs is far more robust and covers a larger area of the rim.

The gas piston on a correctly built AK IS installed to flex. This feature ADDS to the reliability of 7.62 AK.

How do I know?

-I had a "gunsmith" (unfamiliar with AKs) replace the Bulgarian-made & installed piston on my SLR-95 with a U.S.-made piston.

-old piston flexed from the factory.

-new piston installed tight as a drum ("I'll FIX that wobble when I install the new piston!" he told me).

That "fix" turned my reliable AK into a jam-o-matic.

This is all true as well.

[stifled]

When people are talking about the taper helping reliability, is it because the heavy taper helps the cartridge get started into the chamber more reliably/consistently?


I was guessing most of the other things mentioned. It's like most things engineered before the middle of the 20th century--way overbuilt so it can take a lot of abuse! That is obviously only one component to an overall successful design, though.

[spdldr]

If the 5.56 round had a chamber pressure of less than 50,000 PSI and the M4 was adjusted to run with this, the M4 would be much more reliable.

The AK rounds are about 45,000 PSI. The 7.62 NATO is about 50,000 PSI. With the 7.62 NATO/.308 we have the reverse of the 5.56/.223 situation. It is sometimes not a good idea to shoot .308 in a 7.62 NATO rifle as the .308 max pressure can be close to 60,000 and still meet specs.

The 5.56 max. spec. chamber pressure is about 60,000 PSI. High chamber pressure always creates problems with extraction in particular, especially with automatic weapons.

Dave

Boonie Packer

[kal]

This, as well as the combination of the severe taper of the original 7.62x39mm and 5.45x39mm.

That still won't help a thing if the chambers aren't correctly reamed to specs.

I have read that century arms 5.45mm tantals with US made barrels are having trouble with extraction due to tight chambers.

(I am pretty sure there's only one set of chamber dimensions for 5.45mm. How do they fuck that up?)

[dcgallim]

Originally Posted by kal

That still won't help a thing if the chambers aren't correctly reamed to specs.

I have read that century arms 5.45mm tantals with US made barrels are having trouble with extraction due to tight chambers.

(I am pretty sure there's only one set of chamber dimensions for 5.45mm. How do they fuck that up?)

You answered your own question, CENTURY ARMS, they can mess up anything.

[TOrrock]

Originally Posted by kal

That still won't help a thing if the chambers aren't correctly reamed to specs.

I have read that century arms 5.45mm tantals with US made barrels are having trouble with extraction due to tight chambers.

(I am pretty sure there's only one set of chamber dimensions for 5.45mm. How do they fuck that up?)

Talking about real AK's, vs. the post 1989/1994 "kit guns" built for the US civilian market.

Century Arms does not qualify as a well built AK. The Romanian AK's are better than their US made kit guns, and if you get one that runs out of the box, chances are you won't have any issues, but after the 1989 Revolution in Romania, the state controlled arsenals of Ratmil, Cugir, and Romak basically went belly up. The experienced workers left, and the only business that the newly privatized arsenals had was the US civilian market.

Quality control went to shit, Century basically is the Walmart of low end AK's. They tell the Romanians how much they are willing to spend on each rifle, and the Romanians build them to that price point.

K-Var refuses to carry any more Romanian AK parts. The last batch of bolt carriers that they received from them had the gas pistons attached, and everything was in the white. They had assumed that the Romanians would hard chrome the pistons, as is military spec, but figured that they got lazy about the black oxide finish that you'd normally find on a Romanian bolt carrier. So, they attempted to finish the complete bolt carriers in a black oxide bath.

When K-Var pulled the bolt carriers out of the bath, the gas pistons had been blackened as well. That means that they weren't even hard chromed, which is spec for every AK, regardless of country of origin.

The vast majority of the issues I see on US civilian AK's come from reverse engineered US compliance parts, including receivers, barrels, fire control groups, and gas pistons. I've seen US FCG crack, I've seen out of spec US barrels, out of spec and improperly heat treated US receivers with the FCG holes egged out from use.....the list goes on.

I've seen one factory Romanian AK-74 bolt carrier crack at a Vickers AK class. That's honestly the only foreign AK part I've seen malfunction since dealing with AK's since 1987.

[hammonje]

Slop/loose tolerances of parts and the over-gassed operation.

[TOrrock]

Originally Posted by stifled

When people are talking about the taper helping reliability, is it because the heavy taper helps the cartridge get started into the chamber more reliably/consistently?


I was guessing most of the other things mentioned. It's like most things engineered before the middle of the 20th century--way overbuilt so it can take a lot of abuse! That is obviously only one component to an overall successful design, though.

The taper aids in both feeding from the mag to the chamber, and in extraction.

[stifled]

Originally Posted by Templar

The taper aids in both feeding from the mag to the chamber, and in extraction.

Ah OK, interesting. Thanks!

[RAM Engineer]

Originally Posted by Templar

All barrels flex when the weapon is fired.

That's one reason precision rifle barrels are sometimes fluted, and sometimes shorter than you'd expect, because the fluting stiffens the barrel and the shorter barrels flex less.

Technically, fluting does NOT stregthen a barrel or increase it's stiffness.

If you have two barrels, with the same cross-sectional area (and thus the same weight), a fluted one will be stiffer, because it will have a greater O.D., which directly relates to moment of inertia, which in turns means a stronger resistance to bending moments.

It is mechanically impossible to just remove material from a barrel and expect it to increase in stiffness, if you do nothing else to it.

This leaves out any discussion on internal stresses, stress risers, heat treating, etc...

Bottom line: A fluted barrel will be stiffer than a barrel of the same weight, because it will have a greater O.D.

A fluted barrel with the same O.D. as a non-fluted barrel will never be stiffer than the non-fluted one.

[ForTehNguyen]

generous tolerances

[Moose-Knuckle]

What the other have said. . .

"Things that are complex are not useful, Things that are useful are simple."

— Michail Kalashnikov

I would also have to say the magazine of the AK is over built and just damn works. Spetznaz would PT where they would balance themselves on their rifle's mag like a monopod and peform pushups. While being a well balanced ninja has nothing to do with a rifles performance it does say something for how robust the magazine, magazine catch, and magazine catch spring are.