Food for thought: is the luger really a "weak" design?

[Vlim]

I did find some notes on Mauser doing an endurance test with an early Mauser Parabellum. They fired 3000 rounds in succession, using multiple magazines. The pistol was cooled intermittantly in a bucket of water

The gun was ok. Only malfunctions were holdopen fails on empty mags. They did manage to break the bottoms of most magazines. Also the width of the mags changed by .3 mm on average.

[DonVoigt]

Here is the Broken parts list from the FAQ,
thanks 4square for reminding me where it is:

What parts tend to break on
a Luger? (Broken Parts
Survey)
Those of us who shoot our Lugers are alert to
the possibility of breaking the occasional part
on these 60- to 100-year-old guns. Those of
us who collect as well know how much a
broken/replaced part can reduce the value of
our guns.
But, what parts are likely to break in use? This
brief survey was taken in the fall of 2002 to
try to determine a pattern of potential parts
breakage. The intent was to identify parts
which break as a result of shooting, but a
couple other noteworthy results cropped up.
Lugers are a robust, sturdy pistol, designed to
use ammunition more powerful than that
found commercially, at least in the U.S.
Although they are finely crafted (and
considerably hand-fitted) machines, they are
in no way 'fragile'. They are great fun to
shoot, and incredibly accurate. Over the
course of 60-100 years, however, metal can
become fatigued, crystallized, parts can
develop microscopic cracks. Care should be
taken for one's personal safety, as well as for
maintaining the value of our Lugers.
--Dwight Gruber
There were 19 respondents to the
survey, although by the nature of the
answers this represents more actual
pistols than this number.
1. Ejector** 11
2. Take-down spring 7
3. Extractor* 6
4. Grip screw** 3
5. Breech-block* 2
6. Rear toggle piece* 2
7. Hold-open spring 2
8. Firing pin* 2
9. Grip safety spring 1
10. Rear toggle axle pin*** 1
11. Trigger lever pin 1
12. Hold-open* 1
13. Upper receiver* 1
14. Recoil spring, flat 1
* serial numbered part
** proof stamped on Erfurts and most
Simpsons


I do believe this list speaks volumes about the question posed.

[kurusu]

Comment on the list of failures above.

My breechblock failure was atypical. You've seen the pictures. There was a sliver that parted from the side of it. The common fail is the breakage of the rearmost tip that does away with the striker retainer slot rending the pistol inoperable (what happened to mine didn't). This generally happens when by excess of headspace the primers get pierced, the more common cases I've seen (and I've seen or heard of some 4 cases) happened with .30 Luger pistols that used ammo with the bottleneck set to far back. Some folks say that Fiocch ammo is underpowered and causes jams. When getting malfuntions using Fiocchi ammo my advice would be to check if there are pierced primers. If so don't use that lot of ammo in a Luger, there will be no big problems with conventional Browning type actions(besides poor accuracy ) and the fired brass will be correctly fire formed to the chamber and be quite safe for reloading.

[Dwight Gruber]

How does excess headspace cause pierced primers?

--Dwight

[kurusu]

Immediately after firing the pressure dislodges back the primer from it's pocket and slams it hard against the still protruding firing pin, that's how it gets pierced. As the pressure builds up the case also comes back against the breech face relodging the primer in it's pocket.

Edit. The descripted above happens in all situations, but with proper headspace the primer backtravel is kept to a minimum, not enough to piece the primer.

[kurusu]

Originally Posted by Thor

I took these photos. This was a gun that I ended up NOT restoring and was sold by my client to a dealer.

I have seen a number of similar cases in the last 20 years, about 4 that I am aware of, always on DWM or Erfurt toggles, never seen one in a Mauser (never seen a Krieghoff on the firing lines and only saw one refinished Simson and as far as I know it's still without problems). I am convinced that metal fatigue and not overpowered loads are the reason.
I have 2 DWM Lugers, an M2 1909 Portuguese Army contract and a 1916 P08, I have tried them for function (and they funtioned flawlessly) but those are my collector items that won't get shot ever again as long as they belong to me. Even though their collector value is relative. The M2 albeit in excellent original condition was defaced( something I still would like to have a good explantion for) and the 1916 P08 has a few cold blue retouches. Both are all matching. But I do believe those old soldiers deserve a rest.

I have always defended that the best shooters are almost all matching Mauser made P08s.

[DonVoigt]

Thanks Thor,
interesting picture; a crack radiating from a sharp corner is a pretty "classic" metal fatigue type problem. Should have been an easy replacement.

A good lesson for "inspecting" your working firearms when cleaning after use.
Not related to anything, but the retaining pin for the mid-axle has been out and in more than once also.

[4 Scale]

Off topic but to address Kurusu's comment - I just purchased a "defaced" Portuguese Army M2 (M2 crest scrubbed off). Kenyon in "Lugers at Random" notes the crest was removed from some Army M2s but does not address why. In reading the history of the Portuguese Revolution, it seems there was a determined effort to replace old symbols (flag, anthem, official bust) with new ones. Until I find more or better data, I will suspect the removal of the crest was related to this effort.

The lesson I will take from Thor's picture of that Swiss is, next range trip I will do a tape test on all my shooters to verify the toggle strike on the frame is not excessive. Tape test = place a piece of tape at the strike point and inspect.

[Dwight Gruber]

Originally Posted by 4 Scale

...next range trip I will do a tape test on all my shooters to verify the toggle strike on the frame is not excessive. Tape test = place a piece of tape at the strike point and inspect.

Please apply the tape only after you have manually operated the toggle action, and report the results.

--Dwight

[DonVoigt]

Originally Posted by 4 Scale

Off topic but to address Kurusu's comment - I just purchased a "defaced" Portuguese Army M2 (M2 crest scrubbed off). Kenyon in "Lugers at Random" notes the crest was removed from some Army M2s but does not address why. In reading the history of the Portuguese Revolution, it seems there was a determined effort to replace old symbols (flag, anthem, official bust) with new ones. Until I find more or better data, I will suspect the removal of the crest was related to this effort.

The lesson I will take from Thor's picture of that Swiss is, next range trip I will do a tape test on all my shooters to verify the toggle strike on the frame is not excessive. Tape test = place a piece of tape at the strike point and inspect.

On the tape test,
can you not "tell" by just looking at the back of the receiver?
Excessive wear would be apparent, as metal wear or depression.

I've seen a lot of marks, most seem just to have removed the bluing. A few may show a hint of wear. Weapons "re-built" once or twice that I have seen show no significant wear in the metal at
that location.

Do report on the results of your testing- with pictures.
Perhaps even in a separate, instructional thread for those who have no idea what a tape test is.

This potential strike/wear area is related to our previous observation about metallurgy ; an example of where a too hard frame(brittle) would crack if impacted multiple times, instead they are softer(malleable or ductile) so they do not crack-but may show some wear. Harder would eliminate any wear(not to the bluing), but also make the rear of the receiver more likely to crack. Again JMO.

[mrerick]

So... it appears that the evidence discussed in this thread is anecdotal. The 19 results from surveying collectors is probably not statistically significant.

There have been more scientific studies of the Luger design, which is - after all - 115 years after the start of commercial production at this point.

The formal studies that took place involved destructive testing of a number of pistols as well as long term abusive firing of thousands of rounds. There was, of course, politics and market influence involve with the selection of candidates for those military evaluation tests. Even with that consideration, the tests were more comprehensive than anything we have from other sources.

The complete report on the 1907 US Pistol Trials can be downloaded from:

http://www.forgottenweapons.com/wp-c...stoltrials.pdf

This is but one of the comprehensive trials that the Luger was subjected to. Other governments selected the Luger as a service pistol. Switzerland... Germany... But, this is what the US military said at the time:

"The Luger automatic pistol, a lthough it possesses manifest advantage in many particular . . is not recommended for a service test because its certainty of action, even with Luger ammunition. is not considered satisfactory. because the final seating of the cartridge is not by positive spring action . and because the powder stated by Mr. Luger to be necessary for its satisfactory use is not now obtainable in this country."

In essence, they found the design sensitive and unreliable in their testing. They were also concerned about cross-border sources for ammunition components. In effect, a political influence.

The study details the things that broke in their destructive testing.

There were US tests and trials in 1899, 1900, and 1907. During this period, the army "preferred" John Browning's designs, but continued to test other designs. The 1907 field trial was the most extensive, but the 1,000 Lugers were purchased by the US government for trials starting in 1902.

The three .45acp Lugers were procured fo rthe 1907 field trials. Luger subsequently rejected an order for 200 more pistols in 1908, even though it was already considered the third best of everything tested. DWM must have seen the handwriting on the wall - their Luger was not the "preferred" design.

Colt and Savage delivered pistols for the final testing, and (of course) Colt / Browning was selected.

So, considering everything else that was in the marketplace at the time it was designed, I don't think that the Luger was a "weak" design. In fact, it was probably one of the strongest designs that existed in that era. It was not the preferred design for the US Military for a number of reasons, but it was stronger than almost everything else on the market, performed better and was a formidable design. It was also refined, relatively unique, and a vast improvement over the revolver being issued at the time.

Today, after more than 115 years, there have been simpler, more reliable, stronger and longer lasting designs that can fire the 9mm Parabellum and 7.65 Parabellum cartridges. Of course, many things embodying technology have also improved over time - and most at accelerating rates.

Is the Luger Parabellum pistol an old design? Yes - one of the earliest successful semi-automatic pistols. It has been superseded by better and stronger designs - In particular the Pettier SIG P-210 which is a remarkable achievement.

But is the Luger Parabellum pistol a "weak" design? No... I don't think so.

[Michael Zeleny]

Originally Posted by mrerick

Is the Luger Parabellum pistol an old design? Yes - one of the earliest successful semi-automatic pistols. It has been superseded by better and stronger designs - In particular the Pettier SIG P-210 which is a remarkable achievement.

Charles Petter received patents embodied in the French military Modèle 1935 pistol in France (FR782914), Belgium (BE408077), Germany (DE686960), Switzerland (CH185452), and the United States (US2139203). SIG licensed the Petter design in 1937. It served as the starting point for the new Swiss service pistol that realized the culmination of Browning’s tilting barrel design. Max Müller, who headed SIG’s pistol design program, replaced the Browning-style swinging links used by Petter with a novel locking method using a patented kidney-shaped cutout in the lug under the chamber (CH270873, GB673028, FR1002900, and BE492638). The final credit for the SIG P210 belongs to him.

[DonVoigt]

Marc, thanks.
All true for sure, been a lot of water under the dam.

I would only add that the US Trials were for the leaf spring luger, and the change in 1908 to the coil mainspring was a major improvement to the design and it's reliability, but again IMO.

You mention a number of govt. trials, and destructive testing, are these accessible to read, other than the US trials? Reference appreciated, I'd like to read more.

[DonVoigt]

Would someone please add the link to the U tube video of the firing of the "mud test" luger?
I can't get it out of my mind!

[Jim Solomon]

Don,
Try this
https://m.youtube.com/watch?v=z_IeAaR5AmU
Jim

[DonVoigt]

Originally Posted by Jim Solomon

Don,
Try this
https://m.youtube.com/watch?v=z_IeAaR5AmU
Jim

Yes, Jim, that is it. Thanks.

Everyone should watch that video and see for themselves how "sensitive" the luger is.

[Sieger]

Originally Posted by DonVoigt

Yes, Jim, that is it. Thanks.

Everyone should watch that video and see for themselves how "sensitive" the luger is.

Originally Posted by DonVoigt

Would someone please add the link to the U tube video of the firing of the "mud test" luger?
I can't get it out of my mind!

Gentlemen:

Please watch this and its sister video on the Colt 1911 design.

The Luger tested beat the 1911, hands down, in a real world mud test!!

Sieger

[mrerick]

There is a fair summary of earlier trials in the USA in this thread:

http://www.militaryhorse.org/forum/v...ic.php?t=11193

I'm not sure where the Swiss Military Committee reports are available on the web, but their work took place form 1897 through 1899 when they selected the Luger.

[Diver6106]

While I love shooting Lugers, it does have a lot of moving parts and not straight forward like an auto with a slide - now the dominant design. But since the design was for 7.65 Parabellum but then increased to 9mm and even 45 ACP. One would have to conclude it is certainly a robust design.

I bought a WWI DWM with an original broken firing pin, the catch block for the sear was broken off but the metal was all there. It had cleanly cracked at the weakest point, around the base of the block at the tube part. But without careful micro analysis, one could not tell if it was from wear or metallurgy of the time. And as we know, metallurgy improved in the Luger over the years, with Mauser and Kreighoff pistols.

[Edward Tinker]

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tried to read all of the above - I personally have had two breachblock rears blow out, both using 9mm+ ammo - first time was simply that it happened - second time was me using a long barrel luger, 16 inches

both breachblocks were in shooters, but it still happened