Toggle sticking open

[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 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

[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.

[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.

[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 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