[Fixed!] Another Stoeger SxS Not Staying Locked

[John Kloehr]

Since I'm stalled on other projects, got this one out for a closer look.

 

Previous slicking I can identify is beveled chamber tops, bent release lever, and auto safety disabled by cutting rod. But the main spring looks unaltered, I expected it to be cut shorter than stock.

 

Using my micrometer, the locking block can move 0.040" further with the barrels removed compared to the barrels installed. The barrels feel fully engaged, no wiggle I can feel.

 

 

What I can feel and see is the release lever has no play with the barrels removed and can move a small amount with the barrels installed. The block contacts the lever cam when the barrels are removed.

 

 

The point of first contact between the block and lugs is at the green arrows in the next pic. Not sure how this small difference could cause unlocking when shot. Should I remove 0.040 from the leading edge of the block? 

 

Edited April 4 by John Kloehr

[Buffalo gus]

I would paint the lugs or use lay out die, then reassemble the gun. Open and shut it a few times, then look at the wear pattern on the lugs. Mine was barely engaging the lugs, so I filed the locking block until I had solid engagement and also filled the lugs so they were closer to parallel with the barrels. Once I did all of that I had to add a spacer to the lever spring because it had been previously shortened. I’ve had no issues since with featherlites, black powder loads or heavy target loads. From my understanding the very heavy latch spring is to cover up the lack of fitting from the factory. 

[Sam Sackett]

Check out this link for a guide. Sounds like your locking lug needs work to let it travel farther forward into the barrel locking lugs. The second link has the most info on your issue. 
 

http://marauder.homestead.com/files/Stoeger.html

 

http://marauder.homestead.com/files/stoeger2.html
 

Sam Sackett 

[The Original Lumpy Gritz]

Look for a wear mark or burr where the locking block contacts the barrel lugs.

[Garrison Joe, SASS #60708]

Weak release lever spring (top lock lever)  will cause a pop-open on firing as well.  With the release lever having been bent, good chance the spring was lightened or replaced while doing that work.

 

good luck, GJ

[John Kloehr]

More detailed responses later, will be ordering this:

 

 

https://www.amazon.com/gp/product/B000HBM86Q/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&th=1

 

And posting more pics later when it comes in.

Edited February 25 by John Kloehr

[The Original Lumpy Gritz]

2 minutes ago, John Kloehr said:

More detailed responses later, will be ordering this:

 

 

https://www.amazon.com/gp/product/B000HBM86Q/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&th=1

 

And posting more pics later when it comes in.

A sharpie works well 

[El Sobrante Kid]

1 hour ago, John Kloehr said:

More detailed responses later, will be ordering this:

 

 

 

https://www.amazon.com/gp/product/B000HBM86Q/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&th=1

 

And posting more pics later when it comes in.

 

Don't waste your money. Prussian Blue, Dykem, etc. are all for assemblies that are a very, very fine fit... or for layout work. As TOLG commented, use your favorite dark colored sharpie and go to town. It will work just as well for what you are doing. I was a machinist and fabricator for over 35 years and I personally use a blue sharpie for any fitting work that I need to do. GL!

[John Kloehr]

No harm in playing with sharpies, I'm an adult. Illl give it a try and get some bright-light pictures of the lugs and locking bar (I think "locking bar"is the correct term from today's readings of a link posted above).

 

Might be a couple days, have some things pressing tomorrow. But this is the project on my bench at this time.

[Rip Snorter]

Never used a sharpie but a tiny supply of Prussian Blue bought decades back, for no significant amount will work forever, at least my timeline  There is a reason it has been / is used by the pros.

[El Sobrante Kid]

13 minutes ago, Rip Snorter said:

Never used a sharpie but a tiny supply of Prussian Blue bought decades back, for no significant amount will work forever, at least my timeline  There is a reason it has been / is used by the pros.

 

Yes... it is used by the pros, mostly to do layout work. It can also be used to find interference or binding of as little as one thousandth of an inch (.001), or thereabouts, between mating surfaces. The bonus of these layout fluids is that they create a very thin and uniform layer. The fitting work for the shotgun is likely to be 10 times that (.010), or more. In layman's terms .010 is the thickness of about 2-1/2 sheets of paper. So in this case, there is absolutely no benefit in having a layout fluid for this kind of work.

[Buffalo gus]

I will admit that I just used a gold sharpie when I did mine. 

[John Kloehr]

Tried sharpie, can see contact point where I applied it but nothing transferred to the mating parts. Did take some pictures, but ordered some prussian blue. I want to see the transfer to the mating parts.

 

Can report 90% IPA does take sharpie off of steel with no problem.

[El Sobrante Kid]

I'll stop trying to convince you not to get the Prussian Blue, but I will tell you what you should be looking for. When you see the Prussian Blue/Dykem/sharpie transferring to another part, all that it is telling you is that those two parts are "close". A somewhat helpful piece of information. What you are actually looking for is where the Prussian Blue/Dykem/sharpie is being rubbed off. That is the point of interference between the two parts of interest, and that is where you need to remove some material. You remove a small amount of material and you do the whole process again, and again, etc., until you see that the area where the Prussian Blue/Dykem/sharpie is worn off in a pattern that lets you know the two mating parts are engaging the way you want them to. GL!

[Garrison Joe, SASS #60708]

15 hours ago, John Kloehr said:

Can report 90% IPA does

Oh, OK  isopropyl........I was wondering where you got your India Pale Ale that was 90% ethanol. 😄 

 

More pics would be worth a thousand words typed in try to get an explanation of what you do or don't see....

 

What would be real useful to try is taking the locking bar out of action, and hand testing the fit into the locking lugs on bottom of barrel.  And a pic of that.  Your first pics were marked as if the tip of the bar went completely forward into the recess in the front locking lug.  Is this true?  

 

You did not describe how the back cross-piece of the locking bar fits the second locking lug - at the breech.  That seems to be a pretty wide slot!  Does the crossbar on the locking bar fill that slot well?  Check for both full insertion to the depth of slots, and any slack vertically when the bar is full forward in the slots.  No Stoeger will be fit up "perfectly" due to the price point the gun is made to and skill (or lack of) shown by the Brazilian factory worker.

 

If as you have stated the barrels are not able to be even slightly opened when action is closed up, then the lugs and the locking bar are fitted well enough.  That leaves that spring shown in your last picture - the opening lever and locking bar return spring.   You may have to find a stronger spring, or add a spacer (washers, a short piece of tubing, mainly put in to test if a stronger spring would be a permanent fix) to put more force into holding the opening lever closed during recoil.

 

good luck, GJ

Edited March 3 by Garrison Joe, SASS #60708

[John Kloehr]

Got the Prussian Blue and a MMOFT (Massive Moment Of Free Time). Prussian Blue is better/faster than Sharpie but it can easily get everywhere just like anti-seize compound.

 

I did confirm the first contact of the locking bar is at the leading edge of the front tang. And while I can find no play when the action is locked up, I also was able to verify there is no other contact between the tangs and the bar.

 

So the next logical thing is to take back that leading edge until at least one of the tangs engages on bar bevels. My earlier measurements showed the bar moves 0.040 further when the barrel is no in place.

 

So instead, I'm ordering a Stoeger locking bar from Midwest Gun Works. And searching for an original spring too.

 

 

It's worth the educational value to see what an original part looks like, and I like reversible mods.

[Garrison Joe, SASS #60708]

What you are calling tangs are normally called the locking lugs.      So, if I get your drift, right now with the action closed, the locking bars do NOT contact any part of the lugs except at the vertical part of the front lug's recess.  But, that would provide no amount of locking at all.  The lock bar surfaces must "off" of contact with the horizontal parts of the locking lugs, meaning they were poorly fitted at the factory (or later).  You probably need that new locking bar, IF the old one shows file marks from being thinned.  

 

BUT - if the original locking bar has it's full thickness, then metal has been removed from the locking lugs (always the wrong place to try to make a double work better).  A good TIG welder could close up the recesses on both front and back lug, then refit by filing to fit a full thickness locking bar. 

 

good luck, GJ

[John Kloehr]

30 minutes ago, Garrison Joe, SASS #60708 said:

What you are calling tangs are normally called the locking lugs...

Yes, the lugs. And as to the rest of your helpful post, this is a great part why I am ordering a replacement/reference part.

 

This gun was slicked to some degree before I bought it and was apparently trouble-free for the previous owner.

 

I had the opening problem at some point, so sought out and found the recommended Winchester LNLR shells. And it happened again. While I do plan to eventually go to my own hand-loaded brass shells in BP and can tune down to minimum power, the gun is not "safe" for this sport with this problem.

 

If the lugs were filed and I can not fit a replacement bar, I'll send it out to someone with a clue for repair or replace it and sell this one for parts use only. But first I can not turn down a chance to learn as long as I do not make it worse. An eventual upgrade to an SKB would not be a bad thing. In the mean time, I will get some experience with my '97.

Edited March 9 by John Kloehr

[Tall John]

You might find the attached Word document helpful.

Stoeger- How to fix problems with a Stoeger Supreme Shotgun.docx

[Rance - SASS # 54090]

What Garrison Joe said right off the bat…

Strengthen the lever spring.. 
Mine started doing this after I shortened mine..

I put a washer or two to lengthen it back out and WALLA!! Fixed it..

Just sayin’..

[John Kloehr]

27 minutes ago, Tall John said:

You might find the attached Word document helpful.

Stoeger- How to fix problems with a Stoeger Supreme Shotgun.docx 2.31 MB · 3 downloads

Did not have that doc, gone through almost everything on the web. And everything others linked to.

 

I think this doc confirms I am on the right path, though my interference is at the leading edge rather than at the lever cam.

 

I have a replacement lock bar on the way, maybe completely different measurements from mine. But I have no fear of filing or changing the replacement as I can then return to stock on screwing it up.

 

I found a spare spring in a parts box, a Stoeger OEM I ordered a long time ago. By eyeball, it looks the same as the one from the gun. I'll check closer and verify the spring rate later.

 

I think what is happening is the shock from firing shoots the lock straight back if the shock is in that direction (I see 4 surfaces that could do this, and would only need one). If the shock goes through the angled surfaces on the lugs, most of the force is up instead of straight back.

 

Eyeballing the angle with a protector at 10 degrees and taking the sine, only 17% of the shock would be in the rearward direction if the only contact was at the angled portion of the lugs. Right now, it is 100% on the leading edge and zero on the angled portion of the lugs. More later when the replacement part comes in.

[John Kloehr]

Got the replacement locking bar, went through it and the original with my caliper for measurements:

 

 

Then tried a test fit:

 

 

Looks like I need to thin it a bit just to get it into the gun. Looking  at the measurements, I note first that the original is thinner in dimension "C." I also note the new part is already thinner in dimension "F."

 

I think the best approach is to flatten it on the bottom surface to preserve as much as possible to material to engage the lugs. What I am uncertain about is if I should at least do some polishing of the sides and top surface or if it will not matter.

Edited March 16 by John Kloehr

[Buffalo gus]

It surly would t hurt to slick it up. Dimension H is what I shortened to gain more forward movement to engage the lugs. Doing so will probably require a spacer on the latch spring to make up the difference. 

[John Kloehr]

Did a first pass at fitting the new lock bar. It now contacts at dimension "H" in my diagram above.

 

My surfacing setup is a sheet of plate glass with 3M wet or dry sandpaper spray glued to it. Can't remember the grit, maybe 200. It is the coarsest of my four surfaces (2 sheets of glass). I like this setup because it is flat, renewable with a fresh sheet, and does not require as much maintenance as my "real" stones.

 

Each side of the lock bar ended up with 100 passes, the top with 200, and completely lost count of the many passes for the bottom surface.

 

Since I had full forward travel, tried a test fit of the barrel. I will next have to take back a bit of surface at dimension "I" and/or "K." A full swing of the lever does not disengage the bar from the lugs. Pics from today's effort:

 

 

 

 

 

[Garrison Joe, SASS #60708]

You DO NOT have to have the vertical front end of the bar to touch the vertical front lug cavity wall.  So, I'd take metal off the front of bar to the point that something else limits forward travel.  Here is where your dychem or sharpie or prussian blue comes in for tagging the tight spots.  GJ

[John Kloehr]

13 minutes ago, Garrison Joe, SASS #60708 said:

You DO NOT have to have the vertical front end of the bar to touch the vertical front lug cavity wall.  So, I'd take metal off the front of bar to the point that something else limits forward travel.  Here is where your dychem or sharpie or prussian blue comes in for tagging the tight spots.  GJ

It won't touch when I am done. It just means the part is now smoothed to fit all the way into the action. When done, my goal is to have only two contact points, the angled parts of the two lugs. No vertical surface ("G" through "K") should touch when the gun is locked up.

 

But thanks for the guidance! I have enough knowledge to be dangerous but maybe not enough to know what I don't yet know.

 

It was good to walk away for a while. Went back to it and found first I was not being careful enough with positioning the barrel to the pivot position. The lugs do not seem to be jamming the locking bar after all.

 

I then applied some blue to the areas where I do want the bar to contact the lugs (underside surface leading to "I" and "K"). With the barrel in place, I slid the lock bar forward to make contact. Now it definitely does not go as far forward.

 

I found blue transfer on the rear lug so I'll next start filing a slope under and behind "I" so the bar can move forward. I intend to stop and re-assess when I get contact from the front lug under "K." At some point, hoping input here suggests it looks good and I should go test with some shells.

 

I think my "space" to move it forward is just shy of touching the lock cam at "H" (Unless I end up with contact at the vertical surfaces at "I" or "K"). Lots of letter references which only make sense looking at the drawing I posted above. Pictures are better so here is the bar as far forward as it will go with the barrel properly installed, and blue transfer bark on the rear lug:

 

 

 

[Garrison Joe, SASS #60708]

Since you are making contact now on the rear barrel lug (the blue mark), but probably not getting all the way into the rear barrel lug with the locking bar, you may next need to start working a bevel on the underside of the locking bar at position I ("india" phonetically) that matches the angle of the rear barrel lug.  Take a little off, and check if the touching (blue) mark moves slightly forward because now the bar can go slightly farther forward because of the bevel clearing the lug surface.  

 

Be sure you are checking the fit between the barrel lugs and the locking bar while parts are outside the action, too - because the view is so much better doing that.  That is your best guide for getting a great close fit between the lugs and the bar.  Just slide the lock bar into the lugs the same way the opening lever and receiver do it.

 

You should real soon now start to mark (come into contact with) the front lug surface, too.

 

Sounds like you are on the right track!   GJ

Edited March 18 by Garrison Joe, SASS #60708

[John Kloehr]

Did some work today, messed it up early and mostly corrected now as I figure out a technique and the best choice among my tools. I am thinking about diamond-coated files as I am not thrilled with the finish from my hardware-store files. Any input on files or another way to work this part appreciated (not a Bridgeport vertical mill, not doing that). I do not mind buying good tools though.

 

Still no contact at the front lug but it must be getting closer to touching. The rear bevel angle seems close to correct and I will carefully refine it at my next session.

 

The Sharpie has come back out of the office to my gun bench. Very handy for marking the surface I am working and seeing proper tool contact, and high/low spots on the first few swipes. I fixed most of my screwup from earlier today.

 

Expecting a friend over tomorrow, have 4 trees to plant in my "orchard." Thursday is the soonest I will likely be back to this project. A few pics from today:

 

 

 

 

 

Edited March 18 by John Kloehr

[Garrison Joe, SASS #60708]

When I work on something like this with hand tools, I use files first to get rough shape (using fine teeth files - usually sets of needle files).  Fairly light pressure and lots of attention to making a consistent cut across the face of a section which should end up "planar" (a flat).  A sharpie applied before filing tells me where I am "out of flat" after a couple of light strokes.

 

As things get functional, switch to hard "trigger" stones - either very fine carborundum or hard Arkansas or diamond-coated "stones."  Light pressure on those, too.   Even for triggers and sears, that usually puts on a "smooth enough" finish for shotgun actions.  

 

If I need super-polish, then out comes the electric die grinder motor (like a Foredom) and Cratex tips - use very carefully.   Or some grinding compound on a scrap piece of steel or glass that fits the work.

 

good luck, GJ

Edited March 19 by Garrison Joe, SASS #60708

[John Kloehr]

Evened up the work I had started and did another test fit. Both lugs engaged. It seems the last little bit goes fast! Dimension "H" is on the hairy edge of touching and might touch after some test firings. If so, I'll take back the appropriate surfaces; or order more parts if I can't save it.

 

Also tested the lock spring strength, identical to the new one I have.

 

So that is next, time to test fire it. This will require a trip to a range at least an hour away as the local indoor range only allows slugs and 00 Buck, no #8 allowed.

 

Will try to do so in the next few days, Winchester LRLN of course, plus a couple hotter loads I use for other sports. Hoping it has a bit of cushion rather than just barely tolerating the lightest loads.

[John Kloehr]

On 3/18/2025 at 9:29 PM, Garrison Joe, SASS #60708 said:

... lots of attention to making a consistent cut across the face of a section which should end up "planar" (a flat).  A sharpie applied before filing tells me where I am "out of flat" after a couple of light strokes.

 

... switch to hard "trigger" stones - either very fine carborundum or hard Arkansas or diamond-coated "stones."

Yes, slow and easy and consistency and lots of attention needed, I have learned a lot doing this. Certainly not enough to take money from someone to do it for them. My best contribution is maybe this thread documenting what I did and how (or even if) it works.

 

I certainly have more of an appreciation for whatever any of the good smiths might charge to do this work, this gun may still end up with one of them. It is not just a convenience thing, this kind of work takes skill I don't really have. I am glad I did not touch the original part, being able to back out and start over can turn out the best outcome.

 

I am learning about the various stones and diamond-coated files. Have not selected any to purchase yet but I am sure I will at some point.

[John Kloehr]

Fixed! I think.

 

Got to an outdoor range today. Ran 10 shells of Winchester LRNL, then 6 shells of Fiiochi 3-gun (pretty hot stuff). The gun did not open. It might again in the future as things wear in a bit but I have a SxS I can rely on again.

 

In going through parts and receipts, I may have already put an original spring in as an early attempt to fix this. I say this as I ordered 2 springs way back, and have two bags stapled together; one has a spring in it, the other empty. I'll have to check another box later to see if I have what might be the original spring. And maybe go test it as it might be fine to run.

 

Finally, I want to thank everybody who helped with guidance and links to related materials. It all helped!

Edited April 4 by John Kloehr