Magazine springs for new Mauser P.08's

[G.T.]

Hello to all, When I prototyped and produced magazine follower springs, I used the best originals I could get as baseline examples.. One thing I made sure of was that my springs were stronger then the originals... BUT, since making them I have run into situations where the 1970's Mauser Parabellums will not function properly with out an original Mauser post war mag? ... The main difference between the Mauser post war mag and any other mag is spring tension on the follower... You can barely stand to load the Mauser because of the effort needed to depress the follower... but obviously, it is necessary to have the extremely strong spring for function..why? I haven't a clue! Some work fine, some are increadibly fussy... I'm hot on the trail, but would like some feedback and perhaps if some members have any original post war Mauser parabellum mag springs to spare...we can arrange something in trade?? Let me know your thoughts and experiences guys! Best to you, til....lat'r...GT

[Sieger]

Hi G.T.:

As per our earlier discussions, I have found the Mauser Parabellum Spring (9mm) to be an outstanding all around spring for all of my Lugers, 1917, 1941 and 1970s production.

With the right load, this spring functions without fail!! This spring has been nicknamed by me the "Ball Buster" spring as it is certainly strong!! Note that the 7.65 Mauser Parabellum Springs are not the same as the 9mm, per my personal observation.

The Mec Gar springs will function well with a light to medium load, but the Parabellum springs will function well even with a hot load.

My vote goes to the 9mm Parabellum Magazine spring as the all around best you can use in any Luger (including the 7.65mm).

I may have a spare in Florida, but I will have to go down there and loacate it.

Sieger

[G.T.]

OK, here's how it pans out so far.... Mag follower springs in the original post war Mauser Parabellum mags is/are about 40 to 50% stronger then the original pre-45 P.08 luger mag follower springs... They (Mauser Post war mag's & springs) will, & should, work in any, and all, P.08's ever made.... I'm still testing, but preliminary test seem to show that sieger is correct in that a stronger spring is far more desirable then a weak one for a high percentage function... BUT, and this is a big but..... You can't load the damn things!!!! Not even with a tool! 5 rounds, and maybe even 6 ... 7 & 8 rounds and you are for sure going to get a thumb blister! Standard MEC-GAR mags have a spring that is the same as an original mag, although my earlier testing showed that they continuely take a set and as a result eventually drag on the shell itself... but as I go on, I'm more and more impressed by the effort MEC-GAR makes in their mag... for the price, it's a great mag!! My GTHQ spring are an answer to this condition and are designed to function correctly over hundreds, if not thousands of cycles... but, only as a replacement to the original pre 1945 coil spring magazine follower springs... The Mauser Parabellum will take a bit more testing I'm afraid! Best to all, til...lat'r...GT

[Sieger]

[QUOTE=G.T.;158100

You can't load the damn things!!!! Not even with a tool! 5 rounds, and maybe even 6 ... 7 & 8 rounds and you are for sure going to get a thumb blister! [/QUOTE]

Dear GT:

I've never had a problem loading 8 full rounds into an Interarms' Parabellum magazine. You must use the loading tool, however.

The MecGar weight spring is ok for the medium and light strength ammo, but for modern ammo, like the Interarms' pistols were designed to shoot, they are too weak to function reliably.

Sieger

[G.T.]

hi Sieger, When measuring the MP mag follower springs... I had two that were as new, no set, full tension... and 2 that had appearantly taken a full set... probably 10% less then the "as new" springs... and finally, 1 in-between the two sets... The two as new springs were tough to load under even the best of circumstances... and the other three, just slightly less so... I used a tool, but with the extreme tension, it was a clumsy, drop your items type of exercise!! The plastic based mags can't stand too much clumsy.... but, all 5 worked well whether new or old "strong" springs... which leads me to believe a slightly less strength spring, (yet stronger then pre 45 P.08's) would possibly be sufficient to allow for 100% function, and, still be enjoyable to shoot... Now, that being said, I had a 1970's Mauser parabellum in the P.08 style, 4" bbl.. and it worked equally well with any & all mags I put thru it?? But If I have to have that strong of a mag spring to make my luger work, I'm look'en for a different luger!! best to all, til...lat'r....GT

[Sieger]

Originally Posted by G.T.

...which leads me to believe a slightly less strength spring, (yet stronger then pre 45 P.08's) would possibly be sufficient to allow for 100% function, and, still be enjoyable to shoot...

Hi GT:

The hottest ammo I've fired through my byf 41 was the commercailly available Chinese 9mm. This stuff is red hot, hot, hot, and I don't suggest anyone shooting it through their Lugers.

The MecGar would jam with this ammo, the Interarms' wouldn't.

As part of our project, we should settle on a commercial brand of ammo of 124 grains, perhaps pull and reseat the bullets to proper length and test the spring you are developing against it. In this way, ammo of that "heat" and lower should function through the Luger (given a proper recoil spring that matches).

I would probably suggest the S&B 124 FMJ (Brass Case) ammo, as it is about as hot as I feel should be shot through a Luger on a regular basis. The U.S. military load is loaded hotter than 1,200 fps with a 124 grainer, but to me, this is just too hot for regular use in a pistol designed to shoot 123 gr at 1076 fps (the original DWM load listed through the 1930s).

The way I load the Interarms' magazine (mine is probably set by now, with one hundred or so full magazines shot through it), is to set the base of the mag. on the firing bench and then pull down on the loading tool, accordingly. In this way, there is little chance of a slip out of your hand.

I'm sure the Interarms' magazines were designed to function with the commercial German ammo of the 1970s. GECO ammo, for instance, is pretty hot stuff compared to what we were producing, here, during that period.

All the best!


Sieger

[Vlim]

You are correct,

For some more insight, I copied a translation of an article I did for the Dutch ammunition collectors organization (NVBMB). It has been on Jan Still's site for a while:

This is a translation of an article I did for the Dutch NVBMB cartridge collectors club. Enjoy.

The Mauser Parabellum and itâ??s test firing ammunition.

Ammunition and ballistics, the basis of the existence of our club community, play an important role in the development of firearms that will eventually be used to fire that ammunition. That a round, even a standard round like the 9x19mm Parabellum and itâ??s forbearer the .30 Luger, known world wide, will not surrender itself without a struggle is shown in documents from the Mauser archives.

At the end of the 1960s entrepreneurs saw several new markets for and old, classic pistol design: The Parabellum (or Luger) pistol. In the 1950s and 1960s the American consumer market was flooded with cheap military surplus firearms from Europe, annoying the major American arms produces. They feared that these importing activities would have negative effects on their own proceeds and they demanded that legislation to end the import of surplus military firearms was accepted. Interarms, one of the largest importers and distributors of surplus military firearms knew this all too well and decided not to wait for changes in legislation (which were passed in 1969). As early as in 1965, Interarms was in contact with companies like Carl Walther GmbH, Mauser-Werke AG in Germany and the Eidgn. Waffenfabrik in Bern, Switzerland. Discussed was the possibility to reproduce classic sales successes like the Walther P38, PP/K, the Mauser C96, K98, HSc and the Parabellum pistol, if needed even in the USA itself. The American import legislation affected used guns, not new ones.

After long negotiations, Mauser was prepared to take up the challenge and late 1969 the new Parabellum pistol was presented to the general public. We wonâ??t mention that the first demos were actually camouflaged Swiss Model 06/29 Parabellums. Mauser bought a number of Parabellum pistols from the Swiss Eidg. Waffenfabrik, together with Swiss production drawings, sets of quality control and production tools and also received a copy of the design of an automated test firing machine. No doubt that the Mauser Parabellum would be based upon the Swiss design.

Swiss automated test firing machine


One of the most important aspects was to ensure that the Mauser Parabellum repeated correctly, since the pistol type with a toggle lock mechanism responds very critically on subtle changes in ammunition and itâ??s loads. This made selecting the correct reference ammunition very important indeed.

During the first production years it became obvious that feeding issues became a continuing problem, especially with the .30 luger versions of the pistol. After analysis of several P08â??s from DWM and Mauser pre-war production, the curve of the â??frame earsâ?? of the Swiss 06/29 design differed from that of the original German design. The last thing that Mauser wanted to do is to design separate frames for both calibres, so they started to search for a compromise: a frame ear shape that would function in both 9x19mm and .30 luger versions.

On the 5th of January, 1970, Mr. Vorgrimler of Mauserâ??s development department writes about this:

â??Tests with the new uniform curve for .30 luger and 9mm are still in progress. The finished trials prove that by moving the curve 2mm towards the rear the problems will be solved. This also means that the existing frames cannot be altered and these will need to be used up for the .30 luger calibre. The new curve should become available around the end of January, 1970 after the tests with the required ammunitions have been finished. The ammunition in .30 luger from Hirtenberg has not arrived yet. The Genschow company does not produced .30 luger Parabellum ammunition at the moment.â?�


Differences in frame ear curves


The pistol development was also hampered by the mediocre quality of the magazines, produced by Hollandia (later by Metaalwarenfabriek Tilburg) in the Netherlands. Tests proved that especially with 9x19mm rounds the magazines tended to deform rapidly, causing feeding issues. During a 5000 shot endurance test of the 58 magazines used, 32 had fractured bottom pieces.

The comment of Mr. Vorgrimler in 1968, after receiving the First batch of Dutch magazines:

â??On the 29th of October, 1969, 6 Hollandia magazines were handed to mr. Gehmlich, as instructed by manager Fleck. We can state that these magazines show relatively large differences in size and are completely unusable. The very important opening for the magazine catch is placed some 0.7mm lower than it should beâ?¦

â?¦the magazine springs donâ??t meet the requirements, are 50mm too short and donâ??t even come close to the required tension.

Rather than making the part as described on the construction drawings, they made the magazine follower from the rear part of a rimfire hunting round. When a gunsmith, looking for a quick fix for a missing part, comes up with such a solution, he may be forgiven. But when an arms company like Mauser makes such a thing, we can only label it as â??Junkâ??. This would never have happened in the past. Who gave them permission to implement these changes?â?�
In 1970 a new lot of 10 magazines arrives, but these donâ??t satisfy Mr. Vorgrimler either. He comments:

â??The 10 magazines from Hollandia given to the development department show large failures in measurements and cannot be used without modifying them. The magazine lips of weak pressed metal will not survive very long. The Hollandia company wants to deliver new versions, made from pressed steel.â?�

Mauser started testing internally with Remington ammunition. The large number of feeding issues, combined with variations in measurements quickly lead to the suspicion that the Remington ammunition was part of the problem.

In February, 1971 a series of tests were executed using early production pistols in the .30 Luger calibre. 21 pistols were tested and on average each pistol fired some 280 rounds. The most common problems were related to the magazines, owing to the bad quality of those magazines, feeding issues as a result of the Remington ammunition used and the failure of the toggle to remain open after the last shot.

In May, 1971 we see the results of a number of tests with early production pistols in the 9x19mm calibre. Tested were the pistols 1179, 1147, 1219, 1233 and 1223 (the official numbering of production pistols in 9x19mm Parabellum started at number 1152):

5th of May, 1971, pistol 1179:
50 shots, Remington and 50 shots, Winchester. 2 empty cases jammed in the chamber.

19th of May, 1971, pistol 1147:
50 shots, Remington and 50 shots, Winchester. No malfunctions.

25th of May 1971, pistol 1219:
500 shots in total. 400 with Geco ammunition, 50 with Remington and 50 with Winchester. Toggle does not stay open with Geco ammunition 6 times, Once with Remington ammunition, one empty case jammed with Remington as well.

28th of May, 1971, pistol 1233:
A Total of 5000 shots with Geco ammunition. 15 primer failures, 28 feeding failures, 17 jammed empty cases, toggle not fully closed 5 times, Toggle does not stay open after last shot 249 times. 2 broken extractors and 1 broken ejector spring. Of the 58 magazines, 32 bottom pieces broke and 7 additional problems developed.

28th of May, 1971, pistol 1223:
A total of 5000 shots with Geco ammunition. 13 feeding failures, 19 jammed empty cases, toggle does not stay open after last shot 301 times, toggle doesnâ??t close fully 9 times, 2 broken extractors, 1 broken ejector and 1 broken firing pin.

We can see that with the 9x19mm Parabellum the influence of the ammunition was not as important. The problems are mainly caused by the holdopen device, an L-shaped hook that keeps the toggle open after the last shot has been fired. Since this hook is activated by the magazine, the most likely cause was the magazine itself.

The ammunition problem itself was investigated together with the proof house in Ulm. Together with Ulm, Mauser started to search for useable reference ammunition. Tested were the .30 Luger rounds from Remington, Winchester, Norma, GeCo and the Swiss army and the 9x19mm rounds from Norma and the Swedish army. Using the original test reports and internal correspondence we can recreate this search relatively accurately.

Mauser delivered reference ammunition to the Ulm proof house, after which Ulm fired 10 shots per brand and lot number, using a controlled environment. The average of these 10 shots delivered the gas pressure in bar, while the difference between the highest and lowest pressure readings was noted.

In an internal Mauser report, dating from the 2nd of February, 1972, Otto Repa, then responsible for quality control, wrote:

Parabellum test firing ammunition, calibre .30 luger:

The following ammunition brands were shipped to the Ulm proof house:

a. Remington, lot number S 16 S.
The ammunition is not useable for testing. The average gas pressure is some 500 bar below the average operation pressure and shows deviations of +297 / -304 bar. The ammunition is so weak that the toggle does not open completely and the gun will not repeat. According to mr. Brehm some 13,000 rounds are in stock. The same applies to the following lot numbers: Remington S 14 S and S 11 S.

b. Winchester, lot number 7658 DF 1.
The average gas pressure of these rounds is some 2177 bar with deviations of +124 / -112 bar. This ammunition was fired without problems and gave good results, no doubt as result of the careful production.

c. Norma, lot number 08915.
The average gas pressure of these rounds is about 2515 bar and shows deviations of +128 / -411 bar. This ammunition functions some 25% above normal using pressure and shoots very high as a result (highest sight necessary).

d. Geco, lot number march 1971.
The average gas pressure of this round is some 1814 bar and shows deviations of + 136 / -185. Constant good results were had with this ammunition.

Dr. Gminder proposes to use the Swiss and Norma ammunition for the .30 luger calibre.

The management is expected to take a decision on future use of testing ammunition as soon as possible and also to decide what to do with the left over ammunition.

Parabellum test firing ammunition Cal. 9mm.

The following ammunition brands were given to the Ulm proof house for testing:

a. Norma, lot number 06006.
The average gas pressure of this round is 2551 bar and shows deviations of +82/-89. This ammunition should be used in the future, no function problems were encountered and the accuracy is in order.

b. Swedish army ammunition, lot number 07069 90222-9.
This ammunition shows the same properties as the Norma ammunition.

The magazine issues were rectified eventually, after several harsh discussions between Mauser and Hollandia/MFT, although the quality of the Dutch magazines would remain a problem (your author never got his Dutch magazines, produced in 1972, to function properly). Eventually Mauser would use magazines from the Italian MecGar company.

What happened to the unused Remington .30 luger rounds can also be determined from the Mauser archives. In 1977 Mauser sells 3935 rounds of leftover Remington ammunition, deemed â??rejected ammunitionâ?? to Dr. Rolf Gminder, technical manager of Mauser Jagdwaffen GmbH.

That the testing with considerable amounts and brands of ammunition continued at later dates as well can be determined from a, sadly for us, undated report from the Mauser archives. The report shows an overview of 9x19mm Parabellum rounds, their manufacturer, the weight of the bullet, the bullet type, speed and energy. The tests were carried out using a Mauser Parabellum with 6 inch barrel.



With firearms of the Parabellum-type, using a knee joint as a breech mechanism, the interaction between the moving parts, the springs and the ammunition is so critical that it is a challenge to design a standard pistol that can function correctly using the many different ammunition brands on the market. This sensitivity to ammunition and the critical role played by the magazine make for a combination that is very difficult to fine tune, something that can still be seen in the sports shooting world.

We were able to take a look at the work of the Mauser development department, using the documentation kindly provided by Prof. Dr. Rolf Gminder, former technical manager of Mauserâ??s small arms division, Otto Repa, formerly responsible for quality control and Gerd Sch�¶n of the development department. We thank them for the use of this material and the, sometimes colourful, memories they have shared with us.

Attached: Some examples of the Ulm test reports.

[G.T.]

Super information.... at least we're on the right track! So, to condense it down, do we have a design issue with the guns?? Or, a greater issue with the mags?? And, now that i'm on this quest.... is there a cure?? ... ""I've been known to go to great lengths... to solve a problem that doesn't exist!"" Best to all, til....lat'r....GT

[Sieger]

Originally Posted by G.T.

Super information.... at least we're on the right track! So, to condense it down, do we have a design issue with the guns?? Or, a greater issue with the mags?? And, now that i'm on this quest.... is there a cure?? ... ""I've been known to go to great lengths... to solve a problem that doesn't exist!"" Best to all, til....lat'r....GT

Hi GT:

We are faced with certain facts and variables.

1) We have a fixed mechanical design, be it good or bad.

2) We have an opportunity to improve the function of this design over a relative range of commercially available ammo.

3) We can tune the design to function with a given round.

4) We have a good magazine to start our work with, the Mec-Gar magazine.

5) We need to carefully choose our ammo and proceed with the process of designing both magazine and recoil springs to match it, knowing that ammo around that same strength will function within a relative range.

Regards

Sieger

[Sieger]

Vim:

As always, you are a wealth of first rate information.

Do you know how the Germans took the A.O.L. variable into consideration, as the American ammo of the period varied in length considerably. Without proper A.O.L., the design is prone to jamming, as you know.

Sieger

[alterfritz]

I can't contribute much here, I am not a gun tekkie but if you need a Interarms Luger to test something let me know. My gun was made in October 1971 according to this post .
GT has recently fixed some mags for me. Two were mecgar mags which jammed after a few rounds. The first fix didn't do it so I send them back to him and he exchanged the springs for much stronger ones, also fixed something int he original mags (thanks GT ).
Anyway with the ultrastrong springs 4 out of 5 mags now work without a problem with Winchester ammo. I don't know if he put in other followers or if they are still the mecgar, GT can tell more. One of the mecgar mags is still jamming after 4-5 shots, the other performed fine. the original mags that came with te gun now work fine. I guess they were of better quality as the first dutch ones.
Anyway I just wanted to say, if you have anything you want to try out in a 1971 Luger, I'm willing to help. I got so much help in this forum that I thought I offer to do something if you need anything

[G.T.]

Hi Fritz, and we're not done yet! By the time we get this all figured out, we should have a nice, strong, and functional mag for the Mauser parabellum.... got more ideas in the works... On Fritz's problem-matic mag...we have to run it a few more times and see if it works better after taking a bit of a set.. the strongest of the five springs went into the MEC-GAR's... I'll keep ya posted! best to all, til...lat'r....GT