Observations on firing the .30 luger: problems, ammo, springs

[DonVoigt]

4-29-2016
Updating this thread with more results and more info!
See post number 5 below.

There have been three or two threads recently on problems associated with firing 7,65mm or .30 cal luger pistols.

Many of the problems revolve around ammo, sometimes magazines, perhaps springs, and occasionally unknown causes of malfunctions.

We have learned that Fiocchi ammo is not always the same, and it has been confirmed to one member by Fiocchi that they have made changes in the ammo from time to time. Black box, grey box, and purple box Fiocchi seem to have different levels of performance. More to be learned here.

Finnish surplus ball ammo from the mid '50's has been reported to be quite reliable, and is currently available from Samco.

The mainspring or recoil spring is also connected to performance.
Years have taken their toll on original springs, springs have been replaced with "home made"; and several different configuration(sizes) were used in original production.
A compilation is shown attached below.

Magazines are a weak spot for many lugers, current production Mec-gar magazines have been shown to eliminate most magazine related problems.

Given this background, I set out for the range this past week with two different .30 lugers, a DWM alphabet commercial from the mid 1920s, and a 1912 Erfurt that was also re-lined in the '20s for commercial sale. I took three "new" magazines, two mecgars-one chrome, one blue, and a chrome Erma - all new or as new.

For ammunition, I had three types from Fiocchi: round nose jacketed soft point, ball, and hollow point, Winchester hollow point, and Remington ball and hollow point.

I fully expected to find that the hollow points were problematic in feeding and that of the 5 types of ammo, maybe one would work in each pistol. Same for the magazines, i.e. maybe one would be "best".

Pistols were dis-assembled, cleaned, and well oiled before firing.

Well, at the range, surprise!- all ammo worked equally well in both pistols- which is to say no malfunctions.

The Mecgar mags worked well, the Erma did not strip the first round as well as the other two; but they all worked.

I either got lucky or incredibly lucky- or else these .30 lugers are not so sensitive as I was beginning to think.

When i returned home, I checked the mainsprings,
the Alpha commercial had a 17 turn spring(0.056 wire) and the
1912 Erfurt a 19 turn spring of similar wire.

Just a note on replacement mainsprings. Wolf makes three "rated" springs; IIRC 36,38,and 40 lbs ratings- All have 21 or 22 turns, at least that is what was in my kit. Overall length varied by 1/4", but not in relation to the ratings. I think they are all the same. I did buy two spring kits from Sarco, the mainsprings in them are 19 turns- and may be a better choice if you want to replace the springs in a .30.

Though if one studies the chart/info below, one sees that essentially all spring variations have been used at one time or another interchangeably for 9mm and .30 pistols. My apologies for not citing the reference, I do not know the name of the book where it is published.

So - long story short- either nothing or everything works!

I do hope this rambling story is of some help to someone.

[sheepherder]

Originally Posted by DonVoigt

My apologies for not citing the reference, I do not know the name of the book where it is published.

Luger Variations, by Harry Jones, 1959, pg 30.

[rhuff]

Don,

Thanx for your thread. I had sort of found a similar situation in one of my lugers.

I purchased a 1921 DWM alphabet that was all matching many years ago. It remained a safe queen for many years. One day, I decided it was time to start making a range gun out of it, and enjoy it............well I didn't enjoy it at all.

I changed out mainsprings with Wolff Springs of different weights, firing pin springs, sear springs, I don't know how many mags I tried in this gun....many. The story goes on and on.

I am a handloader and tried Winchester and Fiocchi factory ammo, plus at least 8-10 different loadings with different powders, and bullets. I could get it to run somewhat, but never as good as I thought that it should.

It had a really rough feed ramp as a result of being cut with a dull cutter/s. The ridges were horizontal as one would expect. The barrel ramp was rough also. I felt that perhaps the roughness was slowing down the feed mechanism and leading to jams. I did a clean up without changing any angles, and put a polish on both feed ramps.


I found a new mainspring in my cabinet of unknown origin. It had 19 coils. I installed it. That combination of things made my life soooo much nicer.

At this point, that Luger will function with all of my mags(5 different makes), and ALL of my 30 Luger handloads, plus Winchester, Fiocchi, and Finnish military ammo. Needless to say, I plan to change NOTHING on this luger, just enjoy it.


These old girls just have to be correct to be happy, and the owners have to find the correct combination. Boy, when they are correct, they are a real pleasure to own and shoot.

[K.Wilhelm]

With all of the stories I have read about problematic .30 Lugers I must be blessed not having had these issues. One of my 1920's Commercials isn't much to look at but sure can shoot. My handloads with GT's Swiss FMJ bullets and HP-38 powder have worked great from the start. I have actually had more issues with 9mm Lugers. I think it may have something to do with the .30 being the original caliber for the design. Anyway, we've all experienced different sagas on our Luger trails. Bill

[DonVoigt]

Update 4-29-2016

Getting the .30 or 7,65mm luger pistol to "run" can be a real challenge for sure; and it seems all are slightly different.

Some of the "things" that affect performance:
1.0 Ammo
2.0 Magazine
3.0 Mainspring
4.0 Barrel ramp
5.0 Extractor

6.0 Other

I'll try to address them in some logical and understandable order!


1.0 Ammunition: Bullet shape,material, velocity, and over all length(OAL or COA) enter the equation. Here is what I "think" I have learned to date.

1.1 Bullet shape
A round nose projectile, preferably jacketed is most desirable, Fiocchi Round Nose Soft Points will work in some pistols, hollow point projectiles will work in fewer pistols.

1.2 - Over all length
The original spec for the 7,65 mm luger cartridge was for 1.173 OAL
Most and perhaps all modern ammo is shorter in varying degrees.
Recent measurements are below, Fiocchi is found to be the shortest, PPU(Privi Partizan) the longest. I had no Finn ammo to measure, so if someone can advise I'll add it to the list.

Table 1.2
Manufacturer measured : OAL in inches

Winchester: 1.141 to 1.151
Remington: 1.138
Peters: 1.137
Rem-UMC: 1.139 to 1.144

Fiocchi: JSP- 1.114 to 1.119
ball- 1.115 to 1.119

PPU : 1.160

1900 spec: 1.173

So from the short Fiocchi to the long PPU- we see a difference of 0.045" or about 1.1 mm!
Less significant is the Winchester at 1.145 vs. the PPU at 1/160 or 0.015" , but still about 0.1mm

1.3 I have been struggling to get my custom project "baby luger" to function. It has a 2.5" .30 bbl and the grip is shortened 1/2". Thus the mainspring and mass are both changed from the norm. Until today I could not get ANY ammo to feed reliably, getting an "angle" jam at least every other time. Switched to the longer PPU, and the load and function is perfect. NO jams, and locks open. A separate thread will be one on building this "baby" when the project is complete; I plan to have both 7,65mm and 9mm upper assemblies for it, the 9mm is in fabrication with GT.

Which brings us to the Second Problem: the loading, or muzzle velocity.

1.4 - Muzzle velocity ..... to be continued!