Luger - fail to feed

[Dutchman]

1936 S/42. I've fired this Luger before with milsurp Finn machinegun ammo and my own handloads using 124 gr RN FMJ with nary a hitch. Load on both these was 4.7 grs Unique with NOE 134 gr boolit diameter .358". Magazines are Triple K and Meggar and both have worked flawless prior.

About half the time the bolt was failing to strip the top round off. But there were strings of 3, 4 and 5 rds rapid fire that ran like a champion race horse.

I have some ammo from yesterday unfired. First thought is to seat the bullets .005 to .008" deeper and re-run the taper crimp. I used the OAL from Lyman and it wasn't the exact same cast bullet. I will also take some of my older FMJ and run a couple magazines through just to eliminate some unknown possibility. I've shot about 300 rds through this pistol since first acquired in 1998. (Southern Ohio Gun Dist.). It was missing the magazine and had East German police grip panels. Only a couple mis-match numbers. Its a fun shooter.

The S&W MP 4th change: mfg about 1923 and has J.P.D. 33 on the grip. Almost no blue remains. At least 2 factory star stamps indicating factory re-blue. And there are dates stamped into the grip frame from 1933 up to 1971. Despite its hard ~holster~ life the bore is excellent and the double-action is smooth and perfect timing. I shot it rapid fire and it never skipped a beat.

Books:
Fast & Fancy Shooting by Ed McGivern.
Luger Pistols by Fred Datig, revised edition (very outdated)

yes I know... too much LLA

[Delkal]

Lugers need full powered loads to function so switching to lower pressure and maybe a reduced lead load (I didn't check) is probably the problem.

And NO! I don't like loading old and expensive pistols to max but that is what it takes.

[Winger Ed.]

I wouldn't carve on the original recoil spring, however-
If you can find them, you might could get a new spring or two and start shortening them a little at a time
so the bolt will come back all the way for shooting reduced loads.

It'd be the same principal as getting reduced power springs for a 1911 to shoot ammo with reduced 'horsepower'.

[schutzen-jager]

possible limp wrist hold or soft grip ? - did you try a different magazine ? -

[gunther]

Read somewhere that Lugers were originally set up for 125 grain conical flat point bullets before WW1. They may be finicky as to bullet weight.
Round nose bullets were resorted to because the flat point bullets made too much of a wound to suit the German military. They were worried about the Geneva Convention restrictions on firearms and ammunition. Poison gas must not have been mentioned. The Germans did raise cane about the AEF's use of trench guns.

[redhawk0]

I have a P-08 double date 1917/1920. I've been using the Lee 124 conical FP. I was getting some stove piping with mine. A light smoothing of the feed ramp took care of that. If you're not stripping off the next round during the cycle it's likely either a light load or a weak spring in the magazine. I'd try a different magazine first...or pull the magazine apart and give the spring a slight stretch then see if the issue is resolved.

redhawk

[rintinglen]

Mine is a 1938 S/42 Mauser Werke gun, also one of the 90's imports. Mine was supposedly imported from Estonia after the wall came down, but I offer no guarantee of that info. My guess is that given the mags worked with other ammo, the problem is that your loads are not strong enough to drive the bolt back far enough to allow it to consistently pick up the next round. I would not modify the gun. I would first try seating the boolits deeper, if they are longer than 1.08 inches. Second, I'd try raising the load slightly. I'd also make sure that my gun was squeaky clean and well lubed. It doesn't take much in the way of grit or grunge to cause your luger to run raggedly.

My luger won't run unless I am loading right to the top. I use the Lyman 356-242 ~122 grain boolit, and when I started developing a load for it, it was a single shot until I got I got up to 4.2 grains of WW231, and wasn't fully reliable until I was nearly at the book max of 4.5 grains. I use 4.4 grains for the Luger, while most of my other guns run just fine with 4.2 grains under the same boolit @ an OAL of 1.10".

[grayscale]

My 1916 DWM luger (inherited) was an erratic feeder. A new set of springs from Wolfe fixed it and now it runs like clockwork with just about anything I feed it . New springs might help ( sure couldn't hurt)

[Texas by God]

The one Luger that I’ve owned was a 1923 Commercial Safe/Loaded 7.65 ( shooter grade)
I used 100 gr Speer Plinkers and had to use the maximum load for 85 gr bullets to get it to function.
Neat pistols with bad sights was my takeaway!


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[Dutchman]

Mine is a 1938 S/42 Mauser Werke gun, also one of the 90's imports. Mine was supposedly imported from Estonia after the wall came down, but I offer no guarantee of that info. My guess is that given the mags worked with other ammo, the problem is that your loads are not strong enough to drive the bolt back far enough to allow it to consistently pick up the next round. I would not modify the gun. I would first try seating the boolits deeper, if they are longer than 1.08 inches. Second, I'd try raising the load slightly. I'd also make sure that my gun was squeaky clean and well lubed. It doesn't take much in the way of grit or grunge to cause your luger to run raggedly.

My luger won't run unless I am loading right to the top. I use the Lyman 356-242 ~122 grain boolit, and when I started developing a load for it, it was a single shot until I got I got up to 4.2 grains of WW231, and wasn't fully reliable until I was nearly at the book max of 4.5 grains. I use 4.4 grains for the Luger, while most of my other guns run just fine with 4.2 grains under the same boolit @ an OAL of 1.10".

I do have a new Wolfe recoil spring. Not installed. I'll review the load data I used and I'll seat the bullets a touch deeper before I do anything else. I need to backtrack on the previous FMJ I loaded years ago.

thanks for the thoughts
Dutch

[schutzen-jager]

jmho - before changing recoil spring try a different magazine - most of the time mag spring is not pushing cartridge up before breech block passes it -

[Dutchman]

I had a brief moment of clear vision into my visual memory of this incident with the Luger not stripping rds from the magazine. The one thing I forgot to fully describe is exactly where the bolt stopped in it's cycle. It was mid-way up the case. It was not picking up the rim....

Why------ angle of the loaded rd in the magazine is a rather steep angle. The first few loaded went in just fine but I failed to notice that the nose of the bullet was rubbing the front radius of the magazine housing. Too long so they started tipping moreso until the bolt couldn't touch the rim as the cartridge angle was too great. Just enough where it wouldn't feed.

I'll seat the bullets deeper and give it another go next time out. Thanks for all the thoughts and ideas....

Dutch

[Mk42gunner]

I've never had a Luger, but you might try setting your seating depth by running the stem down on a loaded round like we used to do with .45 ACP. That is if you still have some of the rounds that ran flawlessly.

Otherwise, new springs are seldom a mistake.

Robert

[Bigslug]

I've got very little Luger experience under my belt, but I learned quite a bit about how semi autos feed when I experimented with running the TOO LARGE meplat 452423 in the 1911.

Our rounds don't stack in our mags like perfectly parallel cylinders. In the .45 / 1911 combo, there are slight gaps between the fronts of the rounds, and the exact size of that gap varies with the number of rounds in the stack. When the slide hits the back of the top round to feed it, the front of the round nose-dives slightly into that gap. One of the tricks to smooth feeding is to get the round forward enough so that its ogive hits the ramp before the meplat dives enough to hang up on the bottom of the ramp or top of the mag.

The 9x19 cartridge has a rather pronounced taper to it. Might be part of your puzzle.

Also, when you get to the end of your round stack, there's less spring pressure pushing up, and gun climbing in recoil will then have a tendency to cause the heavy bullet end of the rounds to remain in place by their own inertia while the gun climbs without them. The effect is the round can dip into the mag and plow into the bottom of the ramp. I saw this a lot with Glock Gen 3 .40 cals when the recoil and mag spring both started getting tired - slide cycled faster; mag fed slower. Add just a tiny bit of limp-wristing on the part of the operator to cause more muzzle flip, and hang-ups at the top of the mag / bottom of the ramp were pretty common.

[Der Gebirgsjager]

I've got several Lugers, only one S/42. There's no doubt about them being picky about ammo and magazines. If the bolt is overriding the rim and jamming halfway up the case, and the ammo works satisfactorily in other 9mm pistols, I'd suspect the magazine. Could be that the magazine's spring needs to be replaced, but quite possible that that particular magazine just won't work well in that pistol. Then the possibility exists that it won't work well in any Luger. A lot of replacement mags were made here between the World Wars and after WW II that are unreliable and are unmarked. The best original mags seem to be the aluminum based mags. The wood based mags were original equipment to WW I Lugers and usually work well, but it's been over 100 years and they're wearing out. I bought several newly made mags from CDNN with black plastic bases and stainless steel bodies and they work very well. I've heard for years that Lugers prefer hot ammo, but also that it's unwise to use hot ammo in these older pistols as parts breakage can result. I shoot mostly regular velocity FMJ factory ammo in mine...you know, the $15 per box variety like brass Blazer, as they function just fine with it. I really love the Luger pistol, a fascinating design possessing great craftsmanship, but all of this probably goes to the reason(s) why the U.S. Army rejected the Luger after extensive testing and went with the 1911.

DG

[schutzen-jager]

i agree with the mountainhunter, i would try a known good magazine before attempting any thing else -