Toggle sticking open

[Military Engineer]

Hi All,

I hope this finds you well. I have a 1918 Ehrfurt Luger, 4". I use MecGar mags and has been rebarreled within the last 8 years. When I bought it, I was informed that it had new springs. I could not verify that, but the springs feel very new, especially after having to put them in about 4 months ago.

The problem is that the toggle sticks in the open bolt position, but it is not the bolt catch that's doing it.

I fire a round and the bolt sticks open. Using my support side hand, I simply use my thumb to push it back down. It goes home and fires flawlessly the next round. The cycle repeats for every round. The problem is within the last two times at the range.

I reload for it and the recipe is this: 115 gr Berry's, 4.0 gr TiteGroup, 1.145 COL Rounds are clocking at about 1080 fps.

I had one batch seem a little hot the other day, so that was when I chrono'd them and that was what I got.

I thought it might be my reloads, so I used factory ammo and got a similar result. I was told Winchester White box is the standard, so if I can find a box, I will try that. Otherwise...does anyone have any ideas?

[tomaustin]

what lubricants are you applying to the working surfaces...?

the heat from firing may be having an effect......

[G.T.]

Hi to all, best guess that immeadiatly comes to mind is the receiver forks were bent or crushed during the re-barrel effort? Take the upper receiver off and make sure the toggle parts perform properly out of the frame... then reassemble and see if there is any interference between receiver and frame.. correct as needed? Maybe not all as simple as that, but that's where I'd start.... best, GT

[spangy]

I immediately think weak/short mainspring. Maybe try your old original spring again.
Also check the frames breach block slider grooves for dirt/debris.

You also state the gun has been re-barreled within the last 8 years, with the receiver axle pin removed check that the breach block and toggle link assembly slide easily along the length of the receiver without feeling any abnormal resistance. Re-barreling puts incredible stress on the receiver if not done by a competent gunsmith with proper tools for the job.

Good luck.

[Military Engineer]

Originally Posted by tomaustin

what lubricants are you applying to the working surfaces...?

the heat from firing may be having an effect......

For the last 3 years, I use 5W30 motor oil as a lube and a very light coating of high temp bearing grease. This has never been an issue before and I've owned the pistol since 2016.

[Military Engineer]

Originally Posted by G.T.

Hi to all, best guess that immeadiatly comes to mind is the receiver forks were bent or crushed during the re-barrel effort? Take the upper receiver off and make sure the toggle parts perform properly out of the frame... then reassemble and see if there is any interference between receiver and frame.. correct as needed? Maybe not all as simple as that, but that's where I'd start.... best, GT

I might agree, but with rare exception, she was performing very well in the last few years witghout this issue. The gentleman that had it before me mentioned Lugerman as the guy who rebarreled it. I doubt he would have bent the forks.

I will check, though, because for a long time there is a slightly unusualy wear pattern on the rear end of the upper receiver. There is a little resistance to the toggle train going back into the fork when I reassemble. It's always been that way, but never given me the issue before.

I am considering using a finer stone and hand stoning the interior surfaces of the rails in the fork and along the edges of the bolt to smooth up and polish the surfaces.

This is a late WW1 model with rough machine work, and it's already shooter grade owing to the hack job done by someone in the past with the stock lug and the rebarrel, so I'm not too worried about collector value. It's just awfully fun to shoot once in a while but I hate the stickiness of the bolt.

I am also considering main spring replacement, but man...the spring that's in there now is even harder to replace that the one in my Sig 226, so I'm having issues believing it can be the main spring. Once I thumb the bolt forward with just a tap from my thumb, she slams home and fires the next round pretty effectively.

[Military Engineer]

Originally Posted by spangy

I immediately think weak/short mainspring. Maybe try your old original spring again.
Also check the frames breach block slider grooves for dirt/debris.

You also state the gun has been re-barreled within the last 8 years, with the receiver axle pin removed check that the breach block and toggle link assembly slide easily along the length of the receiver without feeling any abnormal resistance. Re-barreling puts incredible stress on the receiver if not done by a competent gunsmith with proper tools for the job.

Good luck.

The main spring has 22 rungs on it. I wonder if that makes much difference, given I think the standard was 19 for the WW1 military ones?

I am considering a main spring (I've been reading up on the subject here in the forum). It just seems like the spring is pretty stout and I believe it was replaced about the same time as the barrel.

I will check the fitting. There is a little resistance to the bolt going back into the forks when I reassemble, but it hasn't been a problem up to now. I always thought that was there to slow the bolt to aid the mainspring in preventing it from slamming back into the rear of the frame. I mentioned to another poster here that I might consider hand stoning with a fine stone the rail grooves in the fork and the rails on the bolt to smooth out/polish/open up the tolerances. It long been a shooter grade, so I'm not horribly worried about ruining collector value. Just do it slowly until the resistance goes away.

Mark

[Vlim]

Is the ejector spring still ok?

[spangy]

Originally Posted by Military Engineer

There is a little resistance to the bolt going back into the forks when I reassemble

22 is the normal coil count for a mainspring. Before I started shaving metal I would exhaust all other avenues.

"There is a little resistance to the toggle train going back into the fork when I reassemble. It's always been that way, but never given me the issue before."

The only resistance one would normally feel would be when the breach bolt engaged the ejector spring when reassembling. Anything above that and I would start to think about the re-barrel warping or altering the fork positions. Grab a caliper and measure the distance between the forks to check for warped forks all along the forks front to back. It should be around .51" give or take .005" but most importantly they should be the same distance all along the forks, front, middle and back, any noticeable distance change would indicate a warped or 'bent' fork. You also must check the vertical orientation but if it was a vertical aberration you would most likely notice that the axle pin would not fit smoothly.

Again though, I would start with the mainspring.

Good luck Mark.

[Military Engineer]

Originally Posted by spangy

22 is the normal coil count for a mainspring. Before I started shaving metal I would exhaust all other avenues.

"There is a little resistance to the toggle train going back into the fork when I reassemble. It's always been that way, but never given me the issue before."

The only resistance one would normally feel would be when the breach bolt engaged the ejector spring when reassembling. Anything above that and I would start to think about the re-barrel warping or altering the fork positions. Grab a caliper and measure the distance between the forks to check for warped forks all along the forks front to back. It should be around .51" give or take .005" but most importantly they should be the same distance all along the forks, front, middle and back, any noticeable distance change would indicate a warped or 'bent' fork. You also must check the vertical orientation but if it was a vertical aberration you would most likely notice that the axle pin would not fit smoothly.

Again though, I would start with the mainspring.

Good luck Mark.

Spangy,

Good onfo. I'll measure tonight. In the meantime, I'm going to order Wolff's gunspring packet for this since it's only a $20 deal or so. If this doesn't solve it, and there is a noticable difference in the fork alignment, is there a fix to this or is it toast and now just a wall hanger? I can't imagine the hardened steel being very amenable to shaping.

[gunbugs]

If the toggle link, the "S" shaped part that hangs from the toggle assy and hooks to the mainspring is bent out of shape, it could prevent return travel.

[Heinz]

Check how the toggle cycles when operating it by hand. Do you feel any binding as it comes to full ****? Also, do this with the grips off and see if the mainspring is binding or hanging up on something. Your description sounds like something is interfering with the camming action, in the same manner, as the hold open stop would and at the same point in the cycle.

[Military Engineer]

Originally Posted by Heinz

Check how the toggle cycles when operating it by hand. Do you feel any binding as it comes to full ****? Also, do this with the grips off and see if the mainspring is binding or hanging up on something. Your description sounds like something is interfering with the camming action, in the same manner, as the hold open stop would and at the same point in the cycle.

This actually is pretty close. Without a magazine in, when I pull the toggle back to open the action, it is a bit tough to do it and the action stays open on it's own, without the hold open operating. I know this because when it was happening at the range, I removed the hold open (so now, in theory, the toggle should NEVER remain open) and it still does it.

Tha main spring does not apparently bind at all, but it does move kind of strangely.

When shooting, it does it after every round and all I have to do is give it a little nudge with my support side thumb and it goes back into battery.

Is there a way to send or upload a video clip (once I figure out how to get one done) to show you guys?

[Military Engineer]

Originally Posted by spangy

22 is the normal coil count for a mainspring. Before I started shaving metal I would exhaust all other avenues.

"There is a little resistance to the toggle train going back into the fork when I reassemble. It's always been that way, but never given me the issue before."

The only resistance one would normally feel would be when the breach bolt engaged the ejector spring when reassembling. Anything above that and I would start to think about the re-barrel warping or altering the fork positions. Grab a caliper and measure the distance between the forks to check for warped forks all along the forks front to back. It should be around .51" give or take .005" but most importantly they should be the same distance all along the forks, front, middle and back, any noticeable distance change would indicate a warped or 'bent' fork. You also must check the vertical orientation but if it was a vertical aberration you would most likely notice that the axle pin would not fit smoothly.

Again though, I would start with the mainspring.

Good luck Mark.

Spangy,

I measured and it is indeed .51. to be exact the maximum "run out", to incorrectly use a machining term, is about .005" or so, so by your numbers it is within spec. Axle pin goes in and out freely.

I'm going to order up a Wolff Gunspring kit tomorrow morning.

[spangy]

I suspect that this only happens when you use a certain brand of ammo ??
Does it happen with various ammo's or just one brand ??
This annoying glitch happened to me years ago and it turned out that the old mag I was using with a certain ammo caused this effect.
The old mag had its feed lips bent outwards over the years which caused the ammo to feed at an angle slightly more upward than is normal ... the ammo I used had a pronounced conical shape that caused it to just brush the barrels upper chamber on the way in.
Like your case a gentle nudge was all that was needed to complete the load.

I restored the mags lip geometry and voila the fix was in.

I never thought I would see this symptom again but maybe that is whats going on with your gun ... or maybe its the mainspring ??
I know Wolf's has a spring package with 3 different load ratings
Reduced Power...: 36 Lb.
Factory Standard.: 38 Lb.
Extra Power........: 40 Lb.
https://www.gunsprings.com/LUGER/cID1/mID38/dID162

It never hurts to have spare springs on hand ... I have several ... so no harm no foul if new springs don't fix the problem.

I 100% know you will fix this Mark and if all the above fails you can still carefully start 'hand fitting' your parts the old fashioned German way.

Good luck again .... I wish I was there to assist .... for me this stuff is fun.

[G.T.]

Hi to all! Without the pistol in hand, I'm not in any position to bark! But I can at least whine a little that maybe on the mainspring as being the issue, you're barking up the wrong tree?....... Even a pooched out, clipped .30 luger mainsprings will initiate closure from the full tension position! The only thing it won't do, is fully close?
So, in the event that the toggle stays stuck in the full travel position, it has to be an interference or lack of available tolerance at that position? So, here's the protocol for that check. First, strip the upper barreled receiver completely. Completely strip the breechblock as well. Now, if you install just the stripped breechblock, it should slide freely from front to back without ANY interference! Any felt interference will be multiplied when operating dynamically.
The measurement between the forks should be .715" ... Also, with a caliper, measure across the chamber, and also measure across the rear receiver forks, and they should be the same.. .939" usually? With the rear main pin installed, and just the breechblock in the receiver, put the abbreviated top end back on the frame, and close the take down lever. Now, everything, the receiver, the breechblock, and the the receiver with the breechblock installed in the frame should slide effortlessly back and forth.. Somewhere in all this, you will find the issue. I'm still betting on a coke bottle shaped crushed or twisted receiver fork will be the culprit??? BTW, try the receiver assembly on a known working Luger? That will tell you a lot as well... best of luck, til...lat'r....GT....

[Military Engineer]

Originally Posted by spangy

I suspect that this only happens when you use a certain brand of ammo ??
Does it happen with various ammo's or just one brand ??
This annoying glitch happened to me years ago and it turned out that the old mag I was using with a certain ammo caused this effect.
The old mag had its feed lips bent outwards over the years which caused the ammo to feed at an angle slightly more upward than is normal ... the ammo I used had a pronounced conical shape that caused it to just brush the barrels upper chamber on the way in.
Like your case a gentle nudge was all that was needed to complete the load.

I restored the mags lip geometry and voila the fix was in.

I never thought I would see this symptom again but maybe that is whats going on with your gun ... or maybe its the mainspring ??
I know Wolf's has a spring package with 3 different load ratings
Reduced Power...: 36 Lb.
Factory Standard.: 38 Lb.
Extra Power........: 40 Lb.
https://www.gunsprings.com/LUGER/cID1/mID38/dID162

It never hurts to have spare springs on hand ... I have several ... so no harm no foul if new springs don't fix the problem.

I 100% know you will fix this Mark and if all the above fails you can still carefully start 'hand fitting' your parts the old fashioned German way.

Good luck again .... I wish I was there to assist .... for me this stuff is fun.

I'm going to retest again with different ammo. I thought my reloads were the issue, so I reloaded a few rounds that are very light...ones I thought would not even cycle the gun because they were under 1100 fps, but they had the same issue. I'm already going to order the spring kits tomorrow, even though I'm relative sure it isn't the spring. You're right...having extra springs is good insurance.

Now...just to be clear: the toggle travels all the way back and stays open. When it does it, it's well behind the magazine. In fatc, it sticks back even without a magazine in it.

It could be the main spring, so I'm going to keep folks in the loop.

[Military Engineer]

Originally Posted by G.T.

Hi to all! Without the pistol in hand, I'm not in any position to bark! But I can at least whine a little that maybe on the mainspring as being the issue, you're barking up the wrong tree?....... Even a pooched out, clipped .30 luger mainsprings will initiate closure from the full tension position! The only thing it won't do, is fully close?
So, in the event that the toggle stays stuck in the full travel position, it has to be an interference or lack of available tolerance at that position? So, here's the protocol for that check. First, strip the upper barreled receiver completely. Completely strip the breechblock as well. Now, if you install just the stripped breechblock, it should slide freely from front to back without ANY interference! Any felt interference will be multiplied when operating dynamically.
The measurement between the forks should be .715" ... Also, with a caliper, measure across the chamber, and also measure across the rear receiver forks, and they should be the same.. .939" usually? With the rear main pin installed, and just the breechblock in the receiver, put the abbreviated top end back on the frame, and close the take down lever. Now, everything, the receiver, the breechblock, and the the receiver with the breechblock installed in the frame should slide effortlessly back and forth.. Somewhere in all this, you will find the issue. I'm still betting on a coke bottle shaped crushed or twisted receiver fork will be the culprit??? BTW, try the receiver assembly on a known working Luger? That will tell you a lot as well... best of luck, til...lat'r....GT....

I'm going to actually do the full strip and see, as you describe. The forks are parallell, by measurement (< .005") and are the same measurement at the chamber and the full travel position.

I'm going to try the springs and a full cleaning including the grooves using things like tiny picks just to make sure I don't have dirt built up in the tiniest spots.

I'll pull out my WW2 Luger and see if it does work. I just know that Lugers are hand fitted, so i wanted to limit the "fitted parts" from complicating the issue across two pistols that are 20+ years apart.

[G.T.]

Hi Mark, it will be interesting to know what is causing the issue? BTW, I have a ton of toggle train parts should you need something to replace or even a part just to try... let us know... best, til...lat'r....GT

[Vlim]

Swap out the L-shaped holdopen and see if it helps.