New 30 luger built up
 

Met an older gentleman at the last gunshow - he bought a few parts from me and I helped him put together a very nice, but mismatched American Eagle. the next day he brought in an 'Erfurt' in parts. He needed a few more parts, but also needed it together. I told him I would put it together and he would let me keep the extra parts, plus any he had to buy. Well, I messed with it, it is a true parts gun. Erfurt toggle, commercial frame with stock lug, other Erfurt parts to make it look better, I put in an old recoil spring etc.

Took it to the range and realized yesterday it was not 9mm like I assumed, but 30 luger. duh.

anyway, took it out with 10 rounds this afternoon. It goes bang every time but toggle just stayed locked, cartridges looked fine (older but nice Remington ammo).

I oiled it excessively and then the last five rounds it would either stove pipe or not open. To tell you the truth, I am not sure if it came open, but I would assume it had to blow back a bit but not kick the round out.

I will check the ejector and extractor

Any other thoughts?

Spring too strong?

Ed

How does the mainspring feel when you manually cycle the toggle train? Does it chamber the cartridge manually o.k.? My first thought is that it is short stroking due to under powdered ammo, or because of an overly strong mainspring. Either would do what you are describing.

I will check tomorrow, it was windy and slightly raining and I just grabbed 10 rounds of Remington. Tomorrow or Friday I will try some Fiochi and some more Remingtons.

Also try a totally different top on it and see what happens in 9mm...

Ed

If it is stove piping the brass, the extractor is functioning on that brass at least. If it is short stroking, it may not even get the spent brass rearward enough for the ejector to perform it's function.

Changing the upper to a 9mm caliber for trial is a good idea. If it performs correctly with it, then your mainspring poundage maybe too much. Good luck.

I believe there are two different springs for the P-08. One for 9mm and one for 30 cal. Might you have a 9mm spring? Also is there an expert who knows what the old craftsmen did to tune up a Luger, besides cleaning and oiling it? Did they cut out loops in the spring or replace it with a less powerful one? That seems to be the primary balancing point for recoil & ejection.

ok, went to a quick range session and here are the results.

Different 9mm top on the built up frame. One stove pipe the rest went pop, pop pop just fine

put the built up 30 luger upper - one shot at a time, but since it is well oiled, was getting stove pipes. My feeling is that the spring is for a 9mm

solution? I have 3 or 4 springs, but what, clip part of this one off, and if so, how much?

for the heck of it, even put the 22 on it - nothing, still can't get it to function even pop one round
ed

Ed,

If you don't know the poundage of any of the recoil springs in your possession (i.e. for 9mm or 30 luger), most folks will start removing one coil of the spring at a time and give it a try. It is truly a trial and error process, even if you have the correct 30 Luger mainspring. These handguns are such a balancing act between springs, ammo, and mags. Did you by chance try any other mags in this Luger?

yes, a nice Mec-Gar and a Vopo mag, so both very good ones.

same results in both uppers

.30 spring
 

Hey Ed! Not to worry, I will send out a .30 spring and some other things tomorrow.... best to you, til..lat'r...GT:cheers: Sorry it's taking so long.. just too many irons in the fire!....:)

Just what IS a 30 cal coil mainspring??? Wolff sells their spring 'kit' with supposedly different poundage ratings, but the same kit is supplied for 30 & 9mm...

Does anyone have a working 30 cal Luger and could measure -

- Wire diameter
- Number of coils
- Spring outside diameter
- Free length

Maybe then we could separate our 'spare parts' mainsprings into 30 and 9mm groupings...

S, The factory DWM .30 cal recoil springs had 17 turns, vis the WW1 9mms that had 19 turns. TH

Tom, do you know the wire diameter??? Wolff's 36/38/40 pound rated springs are all .056" wire diameter and 19, 20, and 21 coils respectively. (I take these pound ratings with a grain of salt). :)

Since you have no takers so far, I went down to the safe house and dug out the M2.

Wire diameter .060" 14 coils. The pistol works flawlessly.
No way of knowing if the spring is original to the pistol.

I decided to compare with my BYF 41.

Wire diameter .059" 21 coils. Also works flawlessly.
Also don't know if that spring was ever changed.

Recoil Spring Tension
 

How would you measure the tension of a recoil spring?
Aldo35

I had a rusted WW1 Luger I beat apart with a hammer. After I wire brushed it..2 of the main spring coils had rusted thru and broke off. I put it back in the pistol cause it was the only one I had. It's a flawless shooter. Apparently there is some leeway.

Note that there may be some leeway in a Luger spring, BUT the rear toggle link has a protrusion that hits the frame for the final stop. Elsewhere in this blog it talks about the rear toggle getting cracked, as a part that wears out. I suspect there is a connection as there is no final soft rubber buffer if the toggle reaches the end in a hard recoil.
http://forum.lugerforum.com/showthread.php?t=6491

I just checked 3 of my recoil springs and they measure .053-.054(WD). Two of them are known Wolff springs, one with 17 coils, and the other two with more coils.

Also decided to check my 1915 DWM P08, and again .059" 21 coils. :confused:

I awaiting parts to try then I will snip off a coil from my old coil before trying anything :)

measure....
 

Hi Aldo, to measure any spring they use a combination of weight and distance... On a luger spring it would be measured as to how much weight it takes to make it compress (deflect) On most compression springs, usually one inch, and also all the way compressed which is called "solid" ... then they measure how far it returns to free length, the difference between new free length, and used free length is called set, and will continue to set, degrade, over use/time...... Almost all original 9mm springs are 21 coils. almost all .30 are varied, 18 or 19 coils.....best to all, til...lat'r...GT....:cheers: BTW, no matter if you trim a coil or two.. the spring still has basically the same working rate, all you really change is the preload?... Which on a Luger is very close to the working design range, (spring doesn't move much!) so it might affect closing more so than opening??..... :cheers: