Winchester mod12

madtrapper143 said:
If you have a gap between the chamber ring and the chamber you will have sticky extraction especially with the new style steel headed shot shells. (actually they have been around for a long time now)

Darryl
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Oh, so as long is the fit is tight between the actual barrel and receiver, the little gap that I see between the outside receiver and barrel is ok?
 
Ideally the gap should not exist. The chamber should be tight against the chamber ring and the face of the barrel and mag tube assembly should be tight against receiver face. This tolerance is what the adjusting sleeve achieves. Welcome to the world of Model 12 gunsmithing. There are at least 7 different sizes of adjusting sleeves and it is guess work to find the right one by trial and error. Swapping barrels on Model 12's is not an easy task most times. The gap you have now will effect the position of the slide rod/action slide in relation to the bolt and action slide lock. This can and will cause locking issues with the gun.

Darryl
 
I’m thinking I shouldn’t ever take mine apart again? ... lol
I’ll probably use it to shoot some ducks and geese this fall then retire it. I like to generally shoot at or shoot something with every gun I own, even if I only briefly own it
 
tharkhold said:
Yeah i noticed that and wasnt sure how to adjust it.. I wouldn't have fired it with the gap though.
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You need to undo/remove the screw on the inside face of the barrel.
Pry up the slide lock away from the barrel into the space left from removing the screw.
There is a sleeve with teeth (the teeth engage in the slide lock which you have now pried up and away) turn this COUNTER CLOCKWISE to tighten the fit.
I usually do about two teeth, then slide the lock back down to engage in the teeth again.
Put the screw back in and test it.
It should get tight around the 5 o'clock position. The last bit of turn should take a bit of force for a nice tight fit.

You may have issues with the sleeve inside the receiver not mating up properly with the barrel you swapped. Many of the parts on these are hand fitted/tuned.
If the sleeve inside the receiver is too tall/thick for your barrel, your barrel will be sitting too far forward in the locked position. Can cause problems with cycling, extraction etc
 
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Gldnbear said:
i'm not a gunsmith but ive been around guns for nearly 50 years , i see no evidence of any refinishing , what makes you think that?
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I agree. If it's refinished, whoever did it did a hell of a good job polishing. I think the reason the OP is having such a hard time cycling & reassembly is because the gun is basically NEW!
 
The quickest way to loosen up a model 12 is to take it down over and over for fun or to show others. Excessive taking down can use up all of the adjustment in a hurry. I even take mine apart for annual cleaning by leaving it in one piece. I just turn the mag and push the slide handle forward then I remove the trigger assembly and bolt and clean it. The take down feature is cool but it can wear the gun prematurely. I have a 1958 model 12 and owned a 1962 model 12. The bluing on these late guns is thin and glossy looking and the wood both quality and fit and finish won't compare to earlier guns. Winchester was phasing out the model 12 in the early 1960's and the quality of the build shows.

Darryl
 
Thanks for the replies.. I guess I should post a picture since the outer gap is less than a mm... But the inside (polished face) lines up and I get the distinctive "snap" with the last few degrees of twisting it in. The sound it makes with the new barrel snapping in place is the same as the original one.

I also tried to take the sleeve off, but I stopped when the force required seemed to harsh. Is it a twist off, or a pull off??
 
The sleeve is retained by a toothed dog which is secured by a screw. This screw is visible when looking at the face of the chamber. The dog has to be levered down to disengage the teeth and allow the sleeve to turn. I am afraid to say but to get your gun fitted properly some lathe and milling machine work is required. A different sleeve may do the job but that is shear guesswork. Good model 12 smiths are extinct in Canada now. If anyone knows one let me know.

Darryl
 
madtrapper143 said:
The sleeve is retained by a toothed dog which is secured by a screw. This screw is visible when looking at the face of the chamber. The dog has to be levered down to disengage the teeth and allow the sleeve to turn. I am afraid to say but to get your gun fitted properly some lathe and milling machine work is required. A different sleeve may do the job but that is shear guesswork. Good model 12 smiths are extinct in Canada now. If anyone knows one let me know.

Darryl
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There is a possibility to remove the insert ring from the receiver and have it properly lathed/milled down the thickness of the gap between the receiver face and the barrel.
In theory that would fix the issue.
It's not a barrel receiver tension adjustment issue as we both said already. Technically his situation would be a headspace issue (albeit a bit odd due to the nature of the design). If the insert was properly reduced by a machine shop or any competent gunsmith his barrel should then fit into the receiver flush and he should have no issues.
But if the work is not done perfectly to ensure it's flush and square cut, you could have all sorts of problems as he starts to use the shotgun.
It's true sadly, there are not many old timers left anymore who truly know how to tune these old beasts.

I'm debating how much of an issue he truly has here. If the gap is literally "less than 1mm" as he stated, his barrel should be up against the ring and thus sealed. It may not cause any real issues in function/firing with that minimal of a gap.
It is a shotgun after all not a precision bolt gun or a full auto GPMG with timing considerations and hard heavy and fast forces.

OP, have you cycled any live shells through it? Or even dummy/snap caps? Give it a try and see how the action cycles with regards to chambering and more importantly extraction.
 
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The ultimate test will be live fire. All the work needs to be done to the front half of the gun. If any work is done to the back half the other barrel assembly will no longer fit properly. I think under firing the action slide will override the action slide lock and lock up the works. In any event it is not an ideal situation. 1 mm is 39 thousands just enough play to foul things up in gunsmithing. I think working up to 39 thousand by removing material from the face of the barrel chamber area would work. But as stated this is machine work not dremel or hand file. With the sleeve removed and the barrel trued and leveled you may be able to remove that much with careful sanding on a disc sander. A little backwoods but it may work. Sand and fit sand and fit sand and fit goes the plan.

Darryl
 
madtrapper143 said:
The ultimate test will be live fire. All the work needs to be done to the front half of the gun. If any work is done to the back half the other barrel assembly will no longer fit properly. I think under firing the action slide will override the action slide lock and lock up the works. In any event it is not an ideal situation. 1 mm is 39 thousands just enough play to foul things up in gunsmithing. I think working up to 39 thousand by removing material from the face of the barrel chamber area would work. But as stated this is machine work not dremel or hand file. With the sleeve removed and the barrel trued and leveled you may be able to remove that much with careful sanding on a disc sander. A little backwoods but it may work. Sand and fit sand and fit sand and fit goes the plan.

Darryl
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Yeah for sure.
I would take the approach of the trying to minimize the insert myself. I'm a backwoods type of guy though! ;) Would be slow methodical and painstaking but it could theoretically be done at home with enough care and the right tools.
Milling the face of the barrel/mage tube guide down would be a straight up gunsmith job. I would not even consider it with my capabilities.
OP; I would confidently fire a live shell with that little play if it was my gun but don't take that as a "go do it!" statement for yourself.
Would take it to a range area, try cycling some live shells in a safe direction and see how the chambering, extraction and ejection works using the unlock lever behind the trigger.
If that all went smooth I would fire one live shell. Again carefully pay attention to the cycling of the gun. Once shell is extracted, inspect the base of the of the shell for bulges or obvious signs of head space problems. In a shotgun you will be primarily limited to case head separation/cracks or ruptures of the copper/brass base
Any hard jams in the extraction or headspace pressure signs and you will have to address the issue.
With that minimal gap and it being a straight wall shotgun shell chamber I would not anticipate any issues.
 
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