Question on using +P ammo in Lugers

I didn't want to hijack runscott's Luger thread concerning his Luger problem. Post 22 on his thread advises no +p ammo in Lugers.
I have 3 Lugers, 2-.30 Luger commercial models and 1-9mm, all acquired over 12 years.
The first thing I did on each teardown/checkout was replace recoil and firing pin springs with new ones.
My subsequent range tests with factory ammo showed consistent failures to feed on all three. Insufficient recoil. I have since tailored my reloads for consistent operation in all 3 (I use the tape/toggle method). Reloads are not hot rods but are definitely very warm, well into +P territory.
When I was young I was told by the old soldiers, now long dead, that Lugers needed pretty stiff recoil to function. My range sessions seem to bear this out.
Is there a Luger expert here that can clarify?

not an expert , but own + shoot a few - I would go back to the original springs + try standard pressure 9mm loads with 115 or 125 grain bullets - mine all function with 4.0 to 4.5 grains of red dot + LRN hard cast bullets - I do not have a .30 to comment on -

Not an expert either, but I have always heard that European 9mm Luger is hotter than current US made 9mm Luger.

Tex1001 said:

I didn't want to hijack runscott's Luger thread concerning his Luger problem.

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Thanks but anyone can feel free to hijack any thread I start. I found the additional Luger conversations very interesting, and as I know almost nothing about them, it's all good reading.

I can't give a direct answer but over the years of being involved with handguns the comments about Lugers operating best with 'warmer' ammo have been offered by others.

No expert here either. I have owned a couple Lugers though. For many years, I heard they liked warmer ammo. The latest was a 1938 Mauser. It may have had original springs for all I know. So I tried some Winchester Q4318 124 grain NATO ball ammo. Not quite up to chronographed +P velocities, but warmer than most commercial 124 grain. I don't think I ever got through an entire magazine without one or more malfunctions with the warmer NATO ammo. My gun worked best with the rather lightly loaded factory Federal AE 124 grain ball, just over 1000 FPS in the Luger. Even then, it was not reliable enough to place any trust in.....

now all new commercial ammo domestic or foreign sold in this country are loaded within SAAMI specs - surplus ammo varies greatly - beware of any labeled for sub machine gun use -

I suspect it needs to be assessed on a case-by-case (gun to gun) basis. My limited experience with one 9 mm P08 was that it worked 100% with standard pressure 115 gr FMJ. Changing springs if you are unsure of their vintage seems to be a good idea.

Tex1001 said:

I didn't want to hijack runscott's Luger thread concerning his Luger problem. Post 22 on his thread advises no +p ammo in Lugers.
I have 3 Lugers, 2-.30 Luger commercial models and 1-9mm, all acquired over 12 years.
The first thing I did on each teardown/checkout was replace recoil and firing pin springs with new ones.
My subsequent range tests with factory ammo showed consistent failures to feed on all three. Insufficient recoil. I have since tailored my reloads for consistent operation in all 3 (I use the tape/toggle method). Reloads are not hot rods but are definitely very warm, well into +P territory.
When I was young I was told by the old soldiers, now long dead, that Lugers needed pretty stiff recoil to function. My range sessions seem to bear this out.
Is there a Luger expert here that can clarify?

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A 9mm Luger should work without problems with most standard commercial 124 or 115 grs ammunition.

I have used 115 grs Winchester, 124 grs Geco, 115 grs Sellier & Bellot, 115, 124 and 147 grs from Magtech, 100, 115 and 123 grs from Fiocchi and the warmest of them our military 115 grs from INDEP that are still not +P level(a word of caution here, if you ever come across any 124 grs from INDEP. Do not use them. They were designed for sub machine gun use). As for springs. The original Luger springs, if not tampered with, appear to be indestructible, I don't know of any modern "replacement" springs that come close to their quality.

DWM P.08 original recoil springs should have 19 coils. Mauser made P.08 should have 21 coils. Not sure about the Erfurt pistols, but I suspect 19 coils as well. No ideia on the Simsons and Kriegoffs.

The DWM .30 should have 14/15 coils. No ideia on the ones made by Mauser.

Lugers are very sensitive to "parts swap". Unfortunately the "desire" to have an "all matching" pistol has created a large number of fakes. I have seen "numbers matching" pistols with parts from DWM, Erfurt and Mauser mixed together and the result can vary from a "jammomatic" to a full auto pistol. Sometimes it is better to buy, as a shooter, an ex "Vopo" pistol with forced match parts(meaning the original non matching numbers are crossed out and there are "new" matched numbers next them) because those parts were refitted to the pistol by folks who knew what they were doing.

Kurusu said:

A 9mm Luger should work without problems with most standard commercial 124 or 115 grs ammunition.

I have used 115 grs Winchester, 124 grs Geco, 115 grs Sellier & Bellot, 115, 124 and 147 grs from Magtech, 100, 115 and 123 grs from Fiocchi and the warmest of them our military 115 grs from INDEP that are still not +P level(a word of caution here, if you ever come across any 124 grs from INDEP. Do not use them. They were designed for sub machine gun use). As for springs. The original Luger springs, if not tampered with, appear to be indestructible, I don't know of any modern "replacement" springs that come close to their quality.

DWM P.08 original recoil springs should have 19 coils. Mauser made P.08 should have 21 coils. Not sure about the Erfurt pistols, but I suspect 19 coils as well. No ideia on the Simsons and Kriegoffs.

The DWM .30 should have 14/15 coils. No ideia on the ones made by Mauser.

Lugers are very sensitive to "parts swap". Unfortunately the "desire" to have an "all matching" pistol has created a large number of fakes. I have seen "numbers matching" pistols with parts from DWM, Erfurt and Mauser mixed together and the result can vary from a "jammomatic" to a full auto pistol. Sometimes it is better to buy, as a shooter, an ex "Vopo" pistol with forced match parts(meaning the original non matching numbers are crossed out and there are "new" matched numbers next them) because those parts were refitted to the pistol by folks who knew what they were doing.

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Very interesting thread, Thanks.

Why are amount of coils with the different manufactures? (strength of the metal perhaps!) I have a DWM, just curious!

NYlakesider said:

Very interesting thread, Thanks.

Why are amount of coils with the different manufactures? (strength of the metal perhaps!) I have a DWM, just curious!

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The DWM P. 08 were designed for the original 9 mm with a troncoconic bullet of 124 gr going under 1100 fps. In the 1930s the the load was upped a bit.

schutzen-jager said:

now all new commercial ammo domestic or foreign sold in this country are loaded within SAAMI specs - surplus ammo varies greatly - beware of any labeled for sub machine gun use -

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Ah yes, but how much inside SAAMI specs is the variable. Quite a lot of bulk ammo in the US is so downloaded that it will barely function in a European gun set up for CIP standard ammo or military ammo. This is why I generally use S&B ammo for practice because it seems to be loaded to the limit rather than some unknown (often large) amount within it.

I'm no expert but I've had several 4" standard Lugers and they all functioned well with top shelf Win or Rem ammo. In early 70s I ruined a S&W m39 with SMG 9mm ammo. Lucky for me primers were to hard for Brn HP or I would have ruined one of those also. As dumb as I was when young I avoided stiff ammo in early autoloaders.

QUOTE: DWM P.08 original recoil springs should have 19 coils. Mauser made P.08 should have 21 coils. Not sure about the Erfurt pistols, but I suspect 19 coils as well. No idea on the Simsons and Kriegoffs.

You are correct. I count 19 coils on my wife's 1914 Erfurt Artillery. I doubt it has been replaced since 1914 and I know for a fact it hasn't been since 1943. It has always disliked anything but ball, but has always functioned well with standard US factory loads.

Kurusu said:

As for springs. The original Luger springs, if not tampered with, appear to be indestructible, I don't know of any modern "replacement" springs that come close to their quality.

DWM P.08 original recoil springs should have 19 coils. Mauser made P.08 should have 21 coils. Not sure about the Erfurt pistols, but I suspect 19 coils as well.

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I didn't count the coils when I installed them. They were New Old Stock from Sarco. I changed them simply because I was leery of 70+ year old springs. I do remember that the old springs were almost 1/4" shorter than the new ones.
I'm not a snob collector. These pistols were all purchased as shooters and I'm happy with them. The comment about no +P made me curious, as I'd heard that Lugers need stiff loads.
Thanks for the information.

The first thing people seem to suspect is wrong when a Luger pistol balks is that the ammo isn't 'hot' enough.
I've heard and read all the old stuff about needing hot loads and all that too.

Truth is a Luger will work just fine with nothing more than off the shelf 115gr FMJ commercial Rem/UMC or any thing close to it IF the pistol is fitted up correctly.

Springs are often suspect but in most instances are not any issue at all in New Model Lugers (coil spring recoil style).
Not many people even shoot the earlier flat mainspring type Old Models because of value, so it's probably not worth going in to them. They should be pretty much relegated to the collectors shelf.

The coil mainspring in a Luger if too powerful (heavy) simply demands a heavier load to cycle the toggle action. So why install one?
The factory weight recoil/main spring works just fine.
You need a load that'll pull the upper back as a unit and then still have enough energy to allow the toggles to kick the action open as they engage the ramps on the frame.
If the toggle action doesn't open far enough, the pistol isn't going to function correctly. No different than a 1911 that the slide doesn't recoil quite far enough when fired.

As far as the rear toggle imprinting on the rear of the frame,,if it is battering the frame, then the load is too much. Same as if the slide on a 45 is battering it's frame.
Back off on the load,,no need to go to a heavier main spring .
The heavier spring just makes it harder to manually operate the action and it also slams it shut much harder than it needs be done.
This latter operation can be the cause of FTFeed as the next up cartridge in the magazine isn't quite positioned yet as the breech is closing.

Well you could fix that by a new and stronger Magazine spring!.
Yes, I guess that's a plan. But you're going around in circles .

A good magazine is paramount to the Lugers function.
The strength of the mag spring, the angle the follower sits, wether the mag button drags on mag body or inside of the right grip, ect.
The feed lips shape (very important) on the magazine itself can make or break a Luger from 'working'.

Feed lips are often bent and tweaked on Luger magazines in attempts to make the pistol function correctly. They can get so far out of alignment that feeding is near impossible sometimes. Plier and file marks can mean the end of an otherwise usable magazine. The metal at the feed lips work hardens from the over adjustments and thinning given it and they crack.

Parts changing usually involves some fitting to get the pistol to operate correctly. The replacement part may drop it OK, but wether it functions is another story. Changing Extractor, Ejector (it's own spring, don't over bend it!) can be simple enough. But the pistol may be subject to FTFeed or Eject properly afterwards.
Every part in each Luger made was 'soft fitted' during manufacture. Then heat treated as needed. Then again refitted (hard fitted) before finishing and assembly. All those numbers are there for a reason.

If a Luger , matching or every # in the phone book, won't function satisfactorily don't immediately jump at the ammo as the source of the problem and figure it needs more steam to get 'er workin'.

Some carefull fitting, refitting, tweaking of parts esp the mag, perhaps a replacement can get them to respond nicely.
Mismatched Lugers can be made to work very nicely.
I've found the MecGar repro magazines have worked quite well for me as a substitute in the past. Even then once in a while I find one that isn't quite up to snuff. Part of the game.
Remember that if you buy parts you are getting old orig parts. Stripped from mostly unusable pistols. The parts may be as worn or damaged as the one you have.
Luckily many of the more common small parts are repro'd now, but you still have to be picky as to quality.

2152hq said:

A good magazine is paramount to the Lugers function.
The strength of the mag spring, the angle the follower sits, wether the mag button drags on mag body or inside of the right grip, ect.
The feed lips shape (very important) on the magazine itself can make or break a Luger from 'working'.

Feed lips are often bent and tweaked on Luger magazines in attempts to make the pistol function correctly. They can get so far out of alignment that feeding is near impossible sometimes. Plier and file marks can mean the end of an otherwise usable magazine. The metal at the feed lips work hardens from the over adjustments and thinning given it and they crack.

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My mag feed lips look like hell - so much so that I won't try firing it for the first time until the new mags arrive Monday.

Thanks for the great description of problems that can occur.

From the late sixties (when I first started reading gun magazines) onward, I read that the reason Lugers have such a bad reputation for malfunctions is because European ammunition is hotter then that "puny American stuff". And Lugers were designed to work with the hotter European ammo.


My Luger - a 1916 Erfurt with a Mauser toggle (Russian capture gun) - works just fine with PMC 115 ball.

Bozz10mm said:

Not an expert either, but I have always heard that European 9mm Luger is hotter than current US made 9mm Luger.

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I think that lots of European handgun ammo is warmer than the average American load. I’ve particularly noticed this with Fiocchi.

Bozz10mm said:

Not an expert either, but I have always heard that European 9mm Luger is hotter than current US made 9mm Luger.

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Way back when (late 50s and going forward) that was quoted by a lot of the authors of the era. I always accepted that as plausible as after all the nine MM was designed as a war gun. Even its full name states that, 9mm Parabellum.