Steel cases and the AK-47


Is it fair to say that the AK-47 was designed around the steel case of the M-43 cartridge? Is the difference between steel and brass cases such that specific engineering and design changes be made to a weapon? Are there differences between chamber dimensions for the M-43 cartridge depending on the country of origin and the case material they typically use?

There is a debate on another forum about this and I wanted to hear what the cartridge collector communitiy has to say about the issue…



@ AKMS: Back in Romania I fired during the military service the Romanian made AKM (PM-63) using only Romanian 7.62X39 rimless cartridges having brass cases (mostly manufactured before 1966) and green lacquered steel cases (manufactured not before 1967) and the weapon always worked with no problems. I assume the manufacturer can make a fluted chamber if extraction problems are probable, especially when the shell cases are made of steel and the rate of fire is high. Liviu 11/30/09

  • @ AKMS: When a weapon maker (in our case AK-47s, AKMs, etc.) manufactured guns for export, how was it possible to know in advance what type of 7.62X39 cartridges (brass or steel cases) the weapons would fire during the future in order to make specific designs??? The weapons were not marked “to fire only ammo with brass cartridge cases” or “to fire only ammo with steel cartridge cases.” Liviu 11/30/09


Having been involved in weapon design (small arms)for a number of years, I have never heard of different designs for steel or brass cases. This not to say that a problem cannot occur with a particular type of ammunition. SMG’s fire brass or steel with exactly the same chamber, pistols fire brass or steel with the same chamber so to with MGs. The potential problem is that with the lack of a ‘soft’ pull, the extractor could not work or be damaged. It is normal practice to fire as many types of ammunition through a new design as possible. Many years ago having been gifted many hundreds of steel cased .45ACP I fired them through a 1911 and a Thompson SMG. I was warned that this would break the extractors particularly on the pistol. Many happy rounds later both were still firing!


While the .45 steel-case ammunition works perfectly in Thompson SMGs and the M3 series of SMGs, it has been known to occasionally break a extractor in a Colt Govt. Model pistol. I can attest to that, have had it happen to me firing it. It is, in fact, the only part in a M1911 or M1911A1 I have ever broken in tens of thousands of rounds fired. I doubt, though, that it was a common occurence. It was just my day in the barrel!

John Moss


There is at least one weapons which depends from the case metal, it is the French FAMAS rifle, which was designed to special tolerances according to the use of lackered steel case 5,56x45 cartridges, a national speciality… Please note that I do not speak about the rifling, which also give some more problems.
The French regulation cartridges were made in Atelier de Construction du Mans during several years,following the M193 model. When some stupid eggheads decided that to run such a big cartridge facility was too costly, and closed the factory, the French Army found itself faced to some problems, asif the first brass cased ammo obtained in Canada (IVI) was OK, other orders, from Israel and later Abu Dhabi (Adcom) did not work properly in the first generation FAMAS.

Now in Afghanistan, the French units are obliged to ask from the US remaining lots of M193 ammo…and the question is where to find steel-cased ones …(Russia, Rumania? why not! our Navy already butys its 100 mm ammunition in Bulgaria!!!).

We are many in my country to think that a nation often involved in military operations abroad should have its home-made ammunition, and not be forced to depend from foreign unsafe providers …

But just try to make such things understand to our stupid politicians!

No more comments!!!



[quote=“stuka222”] the French Army found itself faced to some problems, asif the first brass cased ammo obtained in Canada (IVI) was OK, other orders, from Israel and later Abu Dhabi (Adcom) did not work properly in the first generation FAMAS.

In Spain, it happened the other way around. The spanish Santa Bárbara ammo in 5,56 Nato that worked OK in the domestic Cetme L and LC rifles (delayed blowback system), was found to leave too much residue after being fired in the new Heckler & Koch G36E gas-operated rifles. This led to stoppages and other problems.

The first large lots of SS-109 ammo were loaded in 1981 with belgian PRB powder (named Ball Powder WC-844), but later they switched to domestic gunpowder from the Granada factory.


I think I may owe you an extractor John!
The FAMAS was according to the French government Military sale book designed to fire NATO specification ammunition. According to Ezell is his ‘Small Arms Today’ it was the first rifle to be used by NATO to test ammunition. The majority of NATO ammunition is brass cased.I think there is a confusion between a weapon and an ammunition problem. schneider points out the problem. This happens more often than it should. As to the home production of military goods, I think most people would agree. UK gave up 9mm production and purchased from a number of overseas factories, result problems. viu sums it up how do you know what ammunition will be used? Are there any special design features are specific to steel cases in small arms?


I would imagine the AK-47 is manufactured with extremely loose chambers anyway to accomodate all the possible variations of ammunition that may be encountered. Its possibly the most unfussy rifle ever made when it comes to ammunition and AK47 ammunition is probably the most variable military ammunition around because of the sort of countries that make it. Some of it must be downright primitive.

You never hear of AK47s having problems with feeding or extraction. Quite the reverse in fact. It seems to function reliably no matter what ammunition its given. My guess is they sidestep any questions like this by keeping everything so loose it makes no difference. It has a slightly detrimental effect on accuracy but in an infantry rifle its not enough to worry about


I’d have to disagree with the “loose” chamber theory. I have more than a few “AK” types weapons and reload for them. I have not seen any evidence on the fired brass that the chambers are loose or oversized.

I will agree that they are quite reliable. I once did a test where I took 75 different 7.62x39mm cartridges from my dupes and spares box and loaded them into an RPK drum. There were brass cases, GMCS cases, BWS cases, lacquered steel cases and dates from 1950 to the early 1990s. Some was new production and some was grungy battlefield pick-ups. At least 15 countries were represented in this lot. All fed and fired without a hiccup and hit the target…



Then it is time to study the Parabellum pistol :)

It has a, rather unique, stepped chamber design for the 9x19 para cartridge, which provides for an excellent, although somewhat unneccessary, gas seal. The 9x19 case is slightly tapered and a fired case will clearly show the imprint of the chamber step.

The laquered steel cases that Germany manufactured during the war years were causing jams in the Parabellum pistols and the German army did contact Mauser in order to check for a solution, which was a simple one: remove the step.

It is one of the few documented examples of a pistol that has issues with steel cased ammunition, opposed to its brass cased counterpart.

At our range, the problems with steel cased ammunition are usually more related to the lack of quality of the ammunition components. Steel cased Russian ammo damaged a SIG PE90, an AR15, an M14 and an M1 Garand. The only rifle that ate the Russian stuff without much problems was an Israeli .308 conversion of the K98. The only steel cased ammo we are using at the moment is that for a Zastava, which is designed to take it, in 8x57. The rest gets brass and nothing else.


I was following that thread on the other forum. You are never going to convince that guy no matter what you do. He will forever be right in his own mind. If Mikhail Kalashnikov himself slapped him on the head and told him he was wrong, he would start arguing with him too.
As much of a small arms and ammunition expert as that guy was trying to make himself out to be, he self-righteously stated that he “had no idea what the 7.62x38R was” when someone else brought it up. Acting as if the other person was an idiot who had gotten it wrong and was really thinking about the 54R.
Plus, he doesn’t believe things he reads in books, so no amount of documentation would convince him either. I guess that the Battle of Waterloo didn’t take place as far as he’s concerned, since he did not witness it, and he can only read about it in books.

Oh well, what can you do?



Vlim, Very interesting story on the 9mm Luger pistol and steel ammo. I have heard lots of reasons for the markings on some P08 ammo relative to the P08 pistol but your story makes sense.

For my files I’d like to know where this is documented so I can put the info in my files.

I only know of one Luger pistol without a ringed chamber, and that is a “b” prefix pistol that went to US testing in 1903 (I think). This is probably the earlist documented 9mm Luger pistol, although DWM had clearly tested a 9mm version (perhaps in 9mm Borchart-see Sturgess article in IAA anniversary issue) when Georg Luger offered the caliber to the British military in 1902. The other 9mm pistol (also “b” prefix) sent to the US a month or so later had a ringed chamber.

Is there any indication that the Germans ever made Luger pistols without the ringed chamber after the Mauser recommendation???

I have seen (wish I had) a box of Polte 1939 dated CWS case ammo which is some of the first steel case ammo produced since WWI. The sticker on the back said it was for MP-38 only. Clearly there was some concern with the use of steel case ammo in pistols from the early stages if it’s introduction prior to WWII.

Any info on the German concerns and the Mauser report would be appreciated.




Vlim and Lew - I would love to see those reports also. My own personal Luger is a byf-code (Mauser, Oberndorf) P-08 made in 1941 in the 86XX n series. It has the step in the chamber just before the throat of the barrel. Of course, I realize that Mauser continued manufacture of this pistol on thru at least part of 1942, and the the Heinrich Krieghoff factory made Lugers until 1945. Do we have any Luger collectors who can tell us when this feature was discontinued, or if it ever was, in the pre-1945 9 mm Luger pistols?

John Moss


The story will be documented in an upcoming book on the history of the pre-1946 Mauser produced luger pistols. I have no access to the original documents at the moment, but had a chance to study and discuss them. It’s archive material that originated from Mauser itself, through the estate of former Mauser foreman August Weiss, which was saved and kept by former Mauser Jagdwaffen GmbH manager Prof. Dr. Rolf Gminder.

The book on the pre-war Mauser Parabellum production is a project by Joop van de Kant and Don Hallock. It is being prepared for printing at the moment and is expected to appear around april next year.

The modification that Mauser suggested was sent to the Army as late as 1944, so I doubt that it was applied to any production pistols at all. A blueprint of the chamber reaming tool does exist however, and will probably be published in the same book.

Another telltale sign is the warning label on the steel cased ammunition crates.


Thanks Vlim - I look forward to the book. The Luger books still continue to be published, despite the large quantity of them and that is probably good, considering the breadth of the subject matter!

For those not familiar with the label Vlim posted, and do not read German, it basically says “For the Model 1908 Pistol (Luger), Limited Use, Occasional case sticking.”

Edited to remove typos only

John Moss


Very interesting this step in the Luger as it is little documented. Vlim The book will fill the gap, great news. In the mean time some data from my files.
From German Case drawings No.s 13E9105 and 13E9105 show the steel and brass cases to have the same dimension Case mouth 9.56mm. Current SAMMI spec is 9.6mm.
The current CIP and SAAMI chamber drawings have 9.7mm front face of chamber dimension and 9.93mm at chamber mouth.
Drawings from the Royal Bavarian Rifle Factory for the P08 chamber(1914-1918) give the ‘step’ dimensions. The chamber front face dimension is 9.7mm, 5mm back is the step. The step dimension is 9.85mm and at the chamber mouth 10.06mm. The cartridge and basic chamber dimension of all ages are very similar except for the step.
WW1 Luger( DWM) I have just looked at has the step.
What is the step for? Someone must have designed it for a reason as it makes the reamer more difficult to manufacture.Mauser could ream the step out by using a taper from the larger dimension to the smaller.
I think the box marking are more indicative of the source of the steel case problem. Mainly for SMG use.


Proditto - that particular box marking doesn’t put any restriction on the use of the steel-case ammunition within it in the Pistole 38 (Walther P-38). Some boxes don’t restrict usage of the steel-case ammunition at all. Some do limit the use to the Machine Pistol only - “Nur im Maschinenpistolen versciessen.” It probably depended on many factors found in lot testing, although the P-08 certainly was the most sensitive of the two major 9 mm pistols, and both pistols more sensitive than the “burp guns.”

The step in the chamber was to provide a gas seal. Luger initially wanted a case with a shoulder (the result was the so-called “9 mm Borchardt” round, but that was eliminated. The step in the chamber gave him the type of seal he was looking for. He called it, in German, “Kröpfungsliderung” (“offset obturation” in English). This information is from the full explanation of this stepped chamber contain in the article “The Genesis of the 9 mm Parabellum Cartridge,” by Dr. Sturgess, in Issue 444 (continued in Issue 446), July/August 2005, of the Journal of the International ammunition Association, page11. This article should probably be considered essential reading for those interested in both Luger pistols and the 9 mm Parabellum cartridge.

John Moss