Pistor Jaeger with an issue

[Story]

So this is my .62, which worked just fine until it didn't. 

Track of the Wolf The Rifle Shoppe parts, I think, built by Todd Gerding, I was told.

Hammer started falling from the half-cock, dismounted the lock and poked around but can't remember the issue. Fly, maybe?

I'll circle back with pics of the lock's interior.

[Ed Wenger]

Could be the fly.  Could be an issue with the sear.  Could be other things. 

Does it do the same thing when the lock is out of the rifle?  If it does, I would look to the fly or nose of the sear.  I’ve seen sears that chip and don’t engage the half cock notch completely.

If it’s good out of the lock, it might be the trigger applying pressure to the sear.  Sometimes wood swells over time, changing contact points.  A few file swipes to the top of the trigger should fix it, if that’s the problem.       Best,

        Ed

[rich pierce]

(Ed was quicker and posted while I was typing)
Could be an issue with the fly not allowing the sear to settle into the half cock notch.
Could be a weak sear spring.
Could be a worn half cock notch.
Could be the trigger bar or the inlet for the sear bar are preventing the sear arm from falling low enough.
Could be the lock internals are pulled in against the bottom of the inlet, preventing free rotation.
Could be things are gummed up or the bridle screws tightened down too much.
That’s all I’ve got.

[Story]

Thanks for the immediate responses.

I'll endeavor to take pics and do some function tests in tomorrow's daylight.

[Story]

Holds at half-cock, will not hold at full-cock.
Nothing worn leaps out to my eye.

[sbowman]

Story, it sounds like a sear/sear notch interface issue. To verify remove the fly, if I'm correct it will still fall off the full cock notch.  I don't know how hard that rifle has been shot but if the lock builder didn't properly harden the sear and tumbler they can wear at the interface.  I've scratch built 4 locks, two of which are Pistors just like yours, with  The Rifle Shop castings and the casting are pretty soft.

Steve

[Story]

Thanks, @sbowman  - what would you need to see more of to confirm your notions?

[sbowman]

pull the bridle and get a close up pic like the one above. You can also remove the fly and test the sear engagement at the same time.  If I don't get back until later this afternoon it's because I"ll watching Purdue game LOL

Steve

[sbowman]

also what's up with what looks like a half circle dowel in the sear bar hole in the stock, Don't or can't see that in first lock mortice pic?

Steve

[Daryl]

OP:Holds at half-cock, will not hold at full-cock.
Nothing worn leaps out to my eye."

Seems to me, if it stays in 1/2 cock and won't stay in full cock, sear is damaged, full cock notch is damaged or wood is preventing the sear arm from rotating far enough.
The trigger bar might also be to high, but likely one or more of the others.

[Story]

Thanks, y'all.
Will do those tests later.
Remember, it did work until it didn't.

[Daryl]

Which sounds like a break to me - Sear or full cock notch.
Instant happenings are usually simple problems, not combinations of other problems.

[D. Taylor Sapergia]

Thanks, @sbowman  - what would you need to see more of to confirm your notions?

I think what we're seeing in the first picture is the trigger in the sear bar hole.  In that position, the trigger will be interfering with the sear engaging the full cock notch in the tumbler.  I would assume that the trigger can be rotated forward to drop the trigger's arm from sitting up so high.

[Story]

I think what we're seeing in the first picture is the trigger in the sear bar hole.  In that position, the trigger will be interfering with the sear engaging the full cock notch in the tumbler.  I would assume that the trigger can be rotated forward to drop the trigger's arm from sitting up so high.

You are seeing the trigger pulled to the rear, so the sear will be up that high.

The trigger is forward when the lock is inserted.

[Story]

Finally got some time to fiddle with the lock.

Red arrow indicates where the failure to stay at full cock is happening.

[Robby]

Probably too simple but I had a lock do that once. I looked and looked at the full cock notch, even with an optivisor and it looked fine. I took an ice pick and gently ran it down the full cock groove anyway, there was something, I don't know what, compacted in there. it wasn't much and was virtually invisible to me, but it did fix the problem. I hope your solution is that simple, I always figure, if my truck dies on the road, don't pull the engine, check the gas gauge first. Good luck!
Robby

[Eric Kettenburg]

You've clearly got a good half cock notch as per the photo.  That lock uses a fly that revolves around the internal side of the tumbler axis and they can sometimes be a bit trickier than the more common type (presently) that use a fly with a pin.  This is almost impossible to diagnose correctly without the gun in-hand but I strongly suspect you either have an issue with the fly not allowing the sear to seat correctly in the half cock notch, or a problem with the wood in the sear bar hole perhaps swelling or being too tight and not allowing for free movement of the sear.  If it was a trigger/sear issue, it would have given you problems from the start but if the wood in the sear bar hole is swelling it would account for the intermittent nature.  Likewise if the fly or sear was not hardened/tempered properly, there will be wear rather quickly that will change the interaction. 

The first thing i would do is work the lock *out* of the stock and see if it works properly with no outside/wood stock influence.  If so, then more than likely you have an issue with the lock getting wood bound somewhere.  If the lock still does not work properly out of the stock, then at least a part of the problem (there still may be wood binding as a secondary issue) is the mechanical interaction of the lock parts themselves.

This problem is somewhat common and always needs to be approached systematically by process of elimination.

[Story]

The first thing i would do is work the lock *out* of the stock and see if it works properly with no outside/wood stock influence.  If so, then more than likely you have an issue with the lock getting wood bound somewhere. If the lock still does not work properly out of the stock, then at least a part of the problem (there still may be wood binding as a secondary issue) is the mechanical interaction of the lock parts themselves.

That's exactly what I did.

[Story]

Probably too simple but I had a lock do that once. I looked and looked at the full cock notch, even with an optivisor and it looked fine. I took an ice pick and gently ran it down the full cock groove anyway, there was something, I don't know what, compacted in there. it wasn't much and was virtually invisible to me, but it did fix the problem. I hope your solution is that simple, I always figure, if my truck dies on the road, don't pull the engine, check the gas gauge first. Good luck!
Robby

I firmly believe in shaving with Occam's Razor. I'll give it a cleaning once-over and if that doesn't work, disassemble/reassemble.

Thanks.

[Eric Kettenburg]

So it was a half cock issue in the stock, and then a full cock issue out of the stock?

My first suspicion is that the tumbler and/or sear and/or fly are not hardened/tempered properly and there may be some wear occurring that is causing these issues.  Still could be sear/sear bar hole issue too, but my first guess is going to be improper wear.

Just for fun, stick the lock back in the stock, tighten bolts down and work the lock from cock rest all the way back as far as you can pull the cock (  )while at the same time holding the trigger as far as it will travel.  You should feel nothing at all, no contact.  Cock should move completely unimpeded.  Most of the time nobody yanks on the tirgger that hard in use but it will give you a preliminary analysis of whether the sear bar has enough travel, or the sear nose in the lock mortise has enough clearance.

[Story]

So it was a half cock issue in the stock, and then a full cock issue out of the stock?

No.

The issue is the same, both in and out of the stock.

[Eric Kettenburg]

I'm confused then, because your first post states, "Hammer started falling from the half-cock..." but then your post #5 states, "Holds at half-cock, will not hold at full-cock."  To my mind, those are two separate issues.

Just for giggles anyway, try the experiment I describe in my last post.  That will at the least rule out interaction between wood and sear, and will place the burden squarely on the lock itself.

If it is solely an issue with the lock, it's going to be very difficult to diagnose from afar.  Firstly, I would disassemble and specifically look for wear at the nose of the sear, the nose of the fly and most particularly the full cock notch of the tumbler.  Also ensure that the sear spring has adequate tension to hold the sear in the notches with the mainspring removed, then with the mainspring installed.

[Gaeckle]

Finally got some time to fiddle with the lock.

Red arrow indicates where the failure to stay at full cock is happening.

I'll go out on a limb.....take the fly out and see if the lock stays at full cock. You have a single trigger, may be able to operate the gun without the fly. Got a few old guns without flys and have a single trigger and they work. Just a thought

[sbowman]

Story,  the sear is catching the fly and not letting it "click" past the sear when cocking. the fly should be to the left towards the halfcock notch when the lock is fully cocked.  might be a very tiny burr on either the sear or the fly or maybe just some grit/debris interfering. that fly rotates on a pin FWIW. Take the bridle off and check as I suggested earlier. Looks and sounds like an easy fix. check for a burr, dirt etc., clean, lightly lubricate and put back together without over tightening the sear screw and I'm thinking you'll be back in business.  Keep us posted.

Steve