The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Dave McCracken Memorial Shotgun Forum

Reply
 
Thread Tools Search this Thread
Old January 7, 2022, 01:01 PM   #1
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
1950s winchester model 12 bolt does not fully lock into battery

This is a 2 3/4 12 ga with a about a 30" FC barrel its not the heavy duck.

most of the time the shotgun works well however about 1 in 5 shells will fail to extract ( low brass lead for target). As the gun is pumped the spent shell will stay stuck in the chamber and can be pried out with a knife blade. upon inspection I found that the brass on the left hand side is fire formed to the extractor cutout when viewed from the smart end of the gun. This looks like its forcing the extractor off the rim and also causing excessive friction when attempting to extract resulting in the shell remaining in the chamber.

Looking further into this the bolt does not appear to be fully locked into place. Even with a shell racked in one can use a thumb to slide the bolt back and forth about 1/32" this is probably allowing the shell to slide back out in some cases and a section of brass just beyond the rim is un supported.

There appears to be a system in place that would allow a threaded collar to be adjusted however im not sure how this adjustment should be carried out or if its even related to the problem perhaps there is another part I should be inspecting for wear.

Any ideas?

Thanks
GunJam is offline  
Old January 7, 2022, 04:33 PM   #2
stuckinthe60s
Senior Member
 
Join Date: January 31, 2017
Location: Va., Ct., Mo..
Posts: 860
gunsmith time. m12's aren't a simple tinker gun.
as for the fail to extract, sounds like current cheap ammo unless you tell us otherwise. what brand is it?
__________________
Retired Military Aviation
Former Member Navy Shooting Team
Distinguished Pistol Shot,NRA Shotgun/Pistol Instructor
NSSA All American, Skeet/Trap Range Owner
stuckinthe60s is offline  
Old January 7, 2022, 06:43 PM   #3
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
The ammo most used in this is fiocchi shooting dynamics its probably 4 to 6 years old. same story with other brands like federal also about the same year.

This shotgun belonged to my grandfather. It has never worked right in my possession. I can assume it was doing the same thing to the last person who used it.

All of my other shotguns lock up tight and you can not move the bolt back once its been racked forwards not even .001 of an inch as one can not detect any reward movement by touch. The M12 has about 1/32" of rearward travel this comparison is what makes me believe its a bolt lockup problem and not an ammo problem. I hypothesize that the shell and the bolt are moving back out of the chamber about 1/32 of an inch causing the small section of unsupported brass to fire form to the area around it which is the cutout for the extractor.

I cant seem to track down a gun smith in my area who will take this on. Do you have a recommendation /ph number?

Thanks
GunJam is offline  
Old January 7, 2022, 08:42 PM   #4
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
Open the action and feel up into bolt-stop cut-out(recess) in the top of the receiver.
You may find that the back edge of that recess -- where the bolt slides up/into to lock
up the action -- is no longer a smooth/sharp clean edge.

Rather it had been peened back and a edge is now rough/ragged. That's where the bolt slop is coming from.
Note this is a recurrent problem in shotguns that have no disconnector -- like the M-12-- and that have been
regularly & repeatedly slam-fired in their past.
(Ask me how I know )

The only solution is rebuild/then re-machine that bolt recess. That is *not* a simple task due to need to
need to preserve receiver temper.

https://www.shotgunworld.com/threads...problem.74530/
http://smith-wessonforum.com/firearm...ster-bolt.html


Stu Wright passed away not long ago, but see if anyone still answers the phone w/ a recommendation
Wright's Inc.
1104 South Main St. Pinckneyville IL, 62274
(618) 357-8933
(618) 357-8921 fax
[email protected]
They were renowned as THE Model-12 specialists.


ALSO: Check out http://patsgunrepair.com/services.html

.

Last edited by mehavey; January 7, 2022 at 09:08 PM.
mehavey is offline  
Old January 8, 2022, 12:22 AM   #5
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 28,675
If there is a crud build up in the bolt locking recess, it may prevent the bolt from locking up. Not fully locking up will not prevent the gun from firing, and if fired like that, over time actual damage will happen.

And, I think you've got your terms crossed. From the "smart end of the gun" (the butt, looking forward) the extractor is on the right side, its the ejector slot on the left.

Sounds like your gun is firing out of battery (not fully locked up). This is not good and can be dangerously unsafe if the stars line up just right.

This can be fixed, but its not a job for the home gunsmith or the local AR builder who calls himself a gunsmith.

There are few people in the country still around who could do a quality job, and I don't think Winchester is one of them anymore....

As mentioned, if repair requires rebuilding the receiver locking recess, it may cost you more than the market value of the gun.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old January 8, 2022, 01:51 AM   #6
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
The gun is clean. I went through it carefully. it was quite dirty before I cleaned it, however it does not function any better now thats its clean aside from cycling a bit smoother.

If the ejector slot is on the left then yes its fire forming into the ejector slot not the extractor slot as you pointed out.

I will also take a look and try to get pictures of the bolt stop cutout and look for a rolled or otherwise deformed edge. The mental image of grandpa slam firing his m12 doesn't compute butttttt i dont know... what about just excessive use?

Ill look into this further and get back to you guys
thanks again!
GunJam is offline  
Old January 8, 2022, 03:46 PM   #7
FrankenMauser
Senior Member
 
Join Date: August 25, 2008
Location: In the valley above the plain
Posts: 13,400
Excessive wear can do it.
Very excessive.

Or, someone running the shotgun gingerly and not fully locking it before firing.
Once that locking recess starts getting peened, its future known.
__________________
Don't even try it. It's even worse than the internet would lead you to believe.
FrankenMauser is offline  
Old January 8, 2022, 10:50 PM   #8
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
Here are some photos. There is wear on what I believe is the bolt stop cut out (the section responsible for locking the bolt into battery)

yes there is wear but the wear is less than the amount the bolt slops back and forth. Its a pretty macro image and it does look worse in the image than in real life with less zoom. I can see where the blue fades into worn metal and then there is that extra lip and that ridge might be 4 thou probably less. If I just feel it its feels like a clean edge with a just a bit of rough on the face of the cut.

Im going to say that the wear is not significant enough by its self to account for the slop in that bolt

Thoughts?

ps i hope you like the pictures they were quite difficult to obtain because aperture.
Attached Images
File Type: jpg P1130045.JPG (363.7 KB, 134 views)
File Type: jpg P1130046.jpg (212.8 KB, 122 views)
File Type: jpg P1130049.jpg (729.0 KB, 119 views)
GunJam is offline  
Old January 8, 2022, 11:03 PM   #9
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
here is one more from a more side angle in a desperate attempt to show the actually small amount of deformation. I know someone is already thinking im smoking crack for thinking its not that bad based on the other images.

Thanks again guys!
Attached Images
File Type: jpg P1130052.jpg (184.1 KB, 99 views)
GunJam is offline  
Old January 9, 2022, 03:36 AM   #10
mehavey
Senior Member
 
Join Date: June 17, 2010
Location: Virginia
Posts: 6,869
That doesn't look too bad .... (at least compared to what I had to have done
to fix my own grandfather's 1928 Model-12)

See if just changing out the Chamber/Headspace ring won't fix the problem.
mehavey is offline  
Old January 23, 2022, 11:12 PM   #11
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
Hello

Sorry for the late reply ive just now got back around to dealing with this issue.

Okay the head space ring is shown in the below photo best I can tell. From observation the following are what I believe to be true.

1) It threads into the same thread that supports and locks the barrel
2) it is secured by two screws that run parallel with the barrel that prevent it from rotating
3) it can be adjusted in 1 turn increments only despite looking like it could initially have 1/2 turn precision.
4) maybe its not adjustable at all??

Here is the confusion. If I turn that ring in its going to reduce the space between the shell head and the bolt this would remove the slop

BUT... its going to create a gap between the barrel and the ring this is just as bad... right now they fit perfect and the barrel assembly fits snug to the Rx (that integral flange that is part of the feed tube is nice and snug to the face of the Rx)

BUT part 2... its not obvious if that head space ring can even be turned in a 1/2 turn let alone 1 turn or 1.5 turns as there are no obvious amount of threads ahead of that ring in the rightie tighty direction.

with all this in mind its why said "change" and not "adjust" the ring??

where would i get this part?
did this ring change between years? or is the 1912 one the same as the 1960s one?

Thanks

-Gun
Attached Images
File Type: jpg Img_2364.jpg (173.9 KB, 74 views)
GunJam is offline  
Old January 25, 2022, 03:22 PM   #12
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 28,675
Quote:
Here is the confusion. If I turn that ring in its going to reduce the space between the shell head and the bolt this would remove the slop

BUT... its going to create a gap between the barrel and the ring this is just as bad..
Its been a looong time so, my memory could be in error, but as I recall, adjusting the headspace of a Model 12 was something recommended be done ONLY by a qualified gunsmith. And again, if I remember right, involved more than just turning the ring but also re-fitting the barrel to the new position.

This could involve cutting and re-threading the barrel, along with other shop work that is beyond the skill and tools of the average hobbyist.

You need to find a qualified smith with experience in this area and have a chat with them about the best way to proceed. There are a few, still. Recommend you look for someone who specializes in restorations of out of production guns. And, be prepared to pay a premium price for their work.

I don't personally know who to contact, sorry. I've seen some absolutely fantastic work done by Turnbull, rifles and pistols, don't know if they do shotguns, but they likely could tell you who does....
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old March 8, 2022, 07:36 PM   #13
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
So update

1) the headspace ring was cracked and the notches on the sides of it for the ejector and extractor were quite worn out. The ring was replaced and the new one was turned to be a .005 tighter headspace. Smith replaced extractor spring. said it ran well and was not worn out overall in his opinion.

2) I was off one digit on the serial number...its a 1917 make.

Thanks for the help guys!
GunJam is offline  
Old March 8, 2022, 11:10 PM   #14
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 28,675
If the barrel says Model of 1912 its one of the early guns. If it says Model 12 its made later (I think post war, but don't quote me on that).

I know the gun I got for my 16th birthday says Model of 1912 and it was made in the 1920s. Field grade, 30" full. Not the slickest working, but over all the best damn pump gun I've ever had.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old March 9, 2022, 12:54 AM   #15
GunJam
Junior Member
 
Join Date: January 6, 2022
Posts: 8
Yes you are correct about the name change as far as i know (ive heard this from multiple sources) However to mix things up this barrel reads "MOD.1912" I dont see a serial number on the actual barrel however the band on the barrel does match the Rx. I have no reason to believe it was swapped out.
GunJam is offline  
Old March 15, 2022, 02:10 AM   #16
jmstr
Senior Member
 
Join Date: February 24, 2001
Location: San Joaquin Valley, CA
Posts: 1,281
Did the repair work take care of both problems? I heard two- one was extraction/ejection issues and the other was not locking into battery.

The headspace should take care of at least one- and might tighten up the other.

Watch that locking lug in the frame. It looks a bit beat up to me. There is a drop test that you can find on shotgun world forum or other places. This refers to having the gun cocked, measuring the bolt in lockup, 'firing' the gun [no ammo] and measuring how much the bolt 'drops' at that point.

For specific parts and knowledge, I've been very happy with Nu Line Guns in Rhineland Missouri.

I even got lucky and was able to do some problem solving for around 30-45 minutes with a gunsmith one day. And I was an unknown gun owner.



I don't know if you are aware of the argument about whether to use steel shot in the Model 12 or not. Also, I am not sure if you are aware of the differences in barrel metallurgy between the original nickel steel barrel and the winchester proof steel barrels that came out in the early 1930s.

I don't want to presume and create paragraphs of explanation if you do know- so I'll just say to look into these two issues, or respond here [or pm me] to ask for more info.



Trying to 'full auto' fire these [hold trigger and pump like ze germans are charging through your trench] frequently does add to wear/tear, as mehavey referenced.
One of the really interesting bits I learned in researching the Model 12 [also true for pre'74 Ithaca model 37] was that, while it is true that the trigger doesn't have a 'disconnector', the gun is designed to prevent the hammer from following the bolt.
Instead, the cycle of firing with trigger held back is such:
Bang, pull slide to rear to cock/eject, push slide forward and hammer is held back UNTIL bolt locks into battery, and then the mechanism releases hold on hammer and it fires. This system is a deliberate design characteristic, that seems more appropriate to an era with Huge flocks of birds and larger daily limits than today.
Again, the above presumes you have held trigger back the entire time.
The Ithaca 37 works the same way. I have to look at the guts of the Stevens 520/30 series again to verify, but believe that to be true too.
Since around the 1950s, it seems safety became of more concern [look at designs from late 1940s on].
The JC Higgins Model 20 began sales around 1947 [before '46 Sears used Ranger for house brand]. These shotguns were made by High Standard for Sears, and would be sold as the High Standard Flight King after 1963-ish [when Sears shifted to Winchester Model 1200s for house brand]. The JC Higgins had no disconnector also.
The JC Higgins advertised [in the 1950s] that it had a safety design such that it couldn't fire unless you pulled the trigger. The advertisement described how the bolt was designed so that the hammer would ride the bolt, but the hammer couldn't touch the firing pin until it was in battery. As a result, there shouldn't have been enough inertia to push the pin hard enough to fire the gun.
You just wind up with an uncocked shotgun and a live round in the chamber. So, shuck a new round in and try again.
Now, in all honesty, I've read forums where people with JC Higgins talk about being able to slamfire the shotgun. However, every time I've taken the time to ask if they did this with live ammo, or just did a test with a dummy round, the answer was that they did it with a dummy round.
My Model 20 from around 1958 has the hammer follow, but it won't fire anything. Maybe they were different from 1947-1955. I don't know.
BTW: High Standard shifted to the 'modern' disconnector design somewhere between '68 and '72, where you can 'ride the trigger reset' without firing the gun. They were adjusting to the market influence of the cheaper to make Winchester 1200, Remington 870 and Mossberg 500 [similar internally to High Standard- even after copying Remington's double action bar around '70-ish].



The Model 12 is a fun shotgun- you have a great shooting piece, and a great piece of american history. Enjoy!

Last edited by jmstr; March 15, 2022 at 02:18 AM.
jmstr is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:07 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.06621 seconds with 9 queries