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Questions about a Winchester Model 12

Metalo

Aluminum
Joined
Jan 4, 2008
Location
Clinton, Maryland
This is my first post in this section so please bear with me and excuse my lack of proper technical jargon. I inherited a Winchester pump type shotgun a few years back and now that I am becoming a bit more interested in guns I would like to have a better idea of what I have.

One side of the barrel reads "Nickel Steel - Winchester - MOD 12 - 16 GA - MOD"

The other side has a list of patent dates with the last one being July 22 1913.

The serial number is 289xxx and from looking this up online I have determined the date of manufacture to be 1922!

My main concern is that I have been reading that these pre 1927 versions were chambered for 2 9/16 shells. Before learning this I fired (~150) rounds of 2 3/4 No 8 shells through it with no apparent problems. Did I royally screw up?? :willy_nilly: The only issue I noticed was that if I didn't cycle the pump with authority the spent shell would sometimes get stuck in the ejection port. I have also heard that sometimes the chamber of these older guns was modified to accept the 2 3/4 shells. I don't know if this is the case with mine. How does one measure the chamber? (yes this is not my field of expertise) Also how can I determine if it is choked or not? (clearly I am new to this stuff!!). What does the MOD mean after the 16 GA designation on the barrel? The gun is in beautiful condition in my humble opinion. bluing all there with a tiny bit missing on the pump slide and base of the magazine tube. The barrel doesn't have a rib, just a small bead at the end. The barrel is rather long (as compared to other shotguns I have handled) but I have not measured it. Where does one typically start measuring from?

If anyone could enlighten me a bit about this gun I would greatly appreciate it. I am really concerned about the chamber issue and will not be firing it until I am confident I know what length shells I should use.

If it has been modified to 2 and 3/4 could I still use 2 and 9/16 shells to avoid the getting stuck in the ejection port issue? I see they are scarce but still available. Making them would also be an option since it would provide a good excuse to buy more toys... I mean tools!

If any pictures will help I can produce them.
Thanks in advance. Sorry for the long winded post.
-Joe
 
Hey Joe -

Sweet gun you've got there! I love the old model 12's. I have a 12 gauge from 1944 that I redid; I shoot better with that gun than any of my other shotguns. My dad's 16 is a bit older than mine, mid 30's if I recall correctly.

The MOD stands for 'modified' choke.

Longer barrels were the fashion back then, mine has a 30" barrel, some came from the factory with 32" barrels I believe and heard that you could custom order even longer ones. The barrel starts at about the forward edge of the ejection port; measure from there to the muzzle.

I don't have any good answers for your chamber length questions. Hopefully someone else here will jump in (if they do, feel free to correct anything that I've got wrong as well).
 
Model 12

Well I'll try to help out here.
The MOD is because it has a modified barrel unless it has been opened up.
The shells coming out may have hung up because they are to long for the ejection port, and that is caused by shooting 2 3/4 shells in a 2 9/16th chamber.
A good smith will have gauges to tell if it has a short chamber or not, and they can be opened up, but the hanging up problem will still be there unless the port is also opened up...
Or like you mentioned just load them for your chamber, or port......
A great old shotgun no matter what..... it will last longer than you will 'O)
 
The MOD means that the barrel has a {modified} or slightly constricted choke pattern, rather than open choke (none). It is perfect for hunting rabbits, pheasant, grouse and doves.

The only way to determine which length chamber you have is to measure it. If you have a lathe, create a dummy "shotgun shell" out of appropriately sized aluminum bar and make its length slightly longer, 1/8", than the exact same length as a 2-3/4" shotgun shell. Break the edge of the front of the gauge shell you made with a small chamfer. Keep reducing it's length by 1/32" ---facing it off until it will finally chamber in the gun. Then you will know the exact chamber length.

I am not aware of a rim size difference between the different length shotgun shells. If a particular size that you want to use is hanging up in the ejection port, then carfully relieve the ejection port so that they eject freely...

The Model 12 is considered one of the best shotguns ever produced for hunting... much smoother than the aluminum guns Winchester made to replace it (1200 and 1400)..and what is likely considered a safety issue today, makes it really fast on the second, and subsequent shot.

The "flaw" is that if you hold the trigger back, it will fire the next shell loaded as soon as the bolt is in battery...:eek: This is almost as fast as a good semi-auto for the second shot, but you have to know that it will happen or it can cause a really bad accidental discharge. Modern guns use a disconnector like a semi-auto to prevent the second or later shots from discharging until you have released the trigger.

I used to use a Model 12 trap gun (full choke) that was great for "doubles" once you learned how to pump it without losing your sight picture. Wish I still had mine...traded it off years ago for something else I wanted more... can't even remember what it was I traded for now...:confused:
 
Thanks for all the great replies guys. I also consider it to be a wonderful shotgun, although I don't have much experience with other makes. It has been in the family for a long time and that is where it will stay.

As far as the chamber measuring goes I will go ahead and make the dummy shell on my lathe, but since the 2 3/4 shells fit nicely into the chamber all the way up to the rim wouldn't that indicate that it is sized for 2 3/4?

By inspection, I believe the ejection port has not been tampered with and therefore based on date of manufacture it would have been designed to accommodate the 2 9/16 shells.

IF the chamber is indeed 2 3/4 would the use of 2 9/16 shells be a bad thing? I would like to avoid the getting the shells stuck situation without modifying the ejection port.

Thank you all for your input.
 
You need to make your AL. gauge the length of a fired 2 3/4" shotgun shell. The longer shell will easily fit in the short chamber. The problem comes when it opens on firing. There needs to be room for the plastic case to open into. There is not room in a short chamber and so the pressure is greatly increased. Gary P. Hansen
 
After giving it some more thought, you might want to start your dummy shell as Gary has recommended to make sure that someone didn’t have the chamber deepened that far (NOT recommended), and then proceed with the facing operations until you determine the actual chamber length.

Personally, I would not use the shorter 2-9/16” shells much more than occasionally, if at all. Remember that there will be a ridge at the end of the chamber before the barrel starts… if your shell is shorter than the chamber then when the crimp of the shell unfolds, the shot/wad must hit/pass this ridge instead of being a perfect fit… An occasional shot of the shorter shell won’t likely cause any noticeable harm if this was a single shot, but any residue from a shorter shell could be an obstruction on subsequent shots in a repeater shotgun like this. Once you determine the proper chamber length, stick to that length shell would be my best advice.

As far as the shell hanging on ejection... what is hanging up? the rim? How about some photos?
 
I am going to strongly disagree with the idea that it is safe to put a longer shell than intended in any shotgun chamber. A shotgun chamber is designed to be longer than the unfolded length of the shell. As a result it is possible to drop in shells in the unopened state that are too long for the chamber. This condition is common in old shotguns because the shells have changed in length and the old shells had rolled crimps with cardboard wads on the ends. The result was a shorter opened length for the shell when compared to a modern folded shell design. As a result short chambers are common in old guns.
As a modern shell opens up the end of the shell unfolds. The shot and wad pass through the unfolded section and into the barrel. If the chamber is too short the unfolded part of the shell is inside the barrel instead of the chamber. These forces the shot load through a tighter than intended restriction and can increase chamber pressures.
Difficult in extraction is a good indicator that this condition exists.
As to the notion that it is unsafe to shoot a short shell in a long chamber, I disagree, assuming the chamber is designed with a proper forcing cone. We are all aware of 12 gage guns chambered to shoot 2.75, 3 and 3.5” shells.
Modifying the chamber to accommodate longer shells is a second issue. In this case we are dealing with a desirable collectable, so modification is probably not the best course of action. Before any chamber is modified the wall thickness in the area to be modified must be evaluated. If the OD of the barrel starts necking down near the intended modifications, time to pass on modifying.
Get the chamber checked.
Hand load appropriate loads.
Preserve a good gun for your grandchildren.
 
The part of the shell that is hanging up is the front part which unfolds after firing. I will make some measurements and take some photos tonight.

So as I now understand it, if my chamber is 2 9/16 I could have chambered and fired the longer shells (as I did) without realizing the discrepancy and was lucky nothing bad happened.

If I used a bore gauge or inside calipers to find the ridge at the end of the chamber mentioned in previous posts and then determined the depth at which this ridge is located, wouldn't this give me the chamber length?

I am leaning towards the hand loading option, as I think I will enjoy the process and I really don't want to make modifications to the gun.

I went ahead and ordered a book called "the sixteen gauge manual" to begin my edumacation :crazy:
 
You may not be able to find the end of the chamber with calaper or depth mike as some chambers have a cone shaped end, rather than a sharp step.

If you have a lathe, its not a problem to turn a plug the diamenter of the chamber and mark where it stops with a scribe. That will get you within .020 on length if your carefull.
Another option is a chamber casting.

Once you have that measurement, you will need some kind of chamber referance drawings for comparison.
I dont know anything about the book your buying, but it may have the drawings you need.

Good choice going to the literature.
Carefully chosen books have always been a good investment for me. Knowing what you dealing with rather than guessing saves a lot of time and mistakes.

If the books dont have the data you need, measure a fired shell.
If the depth of the chamber is too short, it should be obvious.

In any case find out what you have before starting the handloading path.
 
I, too, have one of these early 16 ga Model 12's, and ran into the same problem with plastic shells that you have. The difference is that I encountered the problem when plastic shells first came out. The paper shells are softer, especially in the crimped area, and easily deform to allow ejection from an unmodified chamber and ejection port. I had the gun modified for 2 3/4" shells by Pachmyr in Los Angeles in the early 70's.

This precise subject has been covered at least once before with pictures and measurements. Take a look at this thread from 2004 for what remains; some of the pictures are no longer online.

You will have to decide the issue of changing a collectible gun for yourself. Sometimes the original unmodified gun is so valuable as to be worth selling and buying several replacements. Sometimes it is more valuable to you to keep the oldster and modify it. It might be possible to make 2 9/16" shells from modern ones (especially if you can find paper shells) but you might have to use the old nitro card and fiber wads instead of the plastic wads to reload since the plastic ones are designed for the longer shells.

If the old thread doesn't answer all your questions, feel free to ask new ones.
 
16 and 20 short chambers Win 12

Both the 20 and 16's were made in the short chambers in the early models. I have altered both chambers and the side of the action to take the 2 3/4 shells. The receiver needs to be cut forward and an angle from the port to the bottom of the shell chamber ring to the forward edge of the shell head which stops the shell into the chamber. This will make room for the case to exit the chamber without hanging up at the edge of the chamber. This was done by grinding the headspace ring down and at an angle to the port side. The port was cut about 3/32 in forward. The ejector didn't need any altering. The chamber needs to be cut deeper by about .150 in. Brownell's may have the info on their site for this operation. I only tell this for you to understand what is happening in the old Win. 12's and not as a guide for you to work on your gun. Take it to a shop with some old timers working and they will know what needs to be changed.

Don't shot the 2 3/4 shells in the short chambers. This builds up too much pressure at the forceing cone and will cause the locking area of the old mod. 12's to hammer out. Then the old breech block will start dropping down too much and you will get a blown up shotgun in you face. When the receiver is past this stage you will need a major job to rebuild the receiver and it is too expenses to have repaired. The collectors value was not considered when we were working on the guns 40 years ago.

I have a tool you can make if you have a dial indicator which will read all things needed for choke work as well as chambering. It reads directly out on the dial and fits any shotgun choke and chamber. If a chamber is swelled anywhere you can see it as you move the tool out of the chamber. Shotgun chokes are set to a standard on the old guns. The new ones with the inserts are a different can of worms.

I will post pictures of my tool which was made in 1964 if anyone would like to make theirs. It is so simply and this design needs to be on the market.
 
"I will post pictures of my tool which was made in 1964 if anyone would like to make theirs. It is so simply and this design needs to be on the market."

I for one, would like to see it. Thanks, Gary P. Hansen
 
Pictures of shotgun choke tool

If this comes through it will show how it was made. The arms are made from spring stock from Brownell's bulk package of flat springs. The curve of the arm under the bottom is close to the same radius of the Starret dial. Notice that the length is 4 inches from the center of the tool in both directions. The pivot point plates are silver soldered at this point. The arms are bent to fit any chamber or choke and you only need about 4 inches inserted for these checks. The diameter of any of the dimensions can be checked using a mic across the end and set back to the dial indicator numbers. Zero the dial after it is inserted into the barrel. It is the quickest way to check a shotgun barrel. I checked the tool with a long depth mic and it is within .001 of the mic dimensions. It will work on any chamber or choke from 410 to 10 gauge. The length of the chambers are marked on the side of the arms so you can see when the forcing cone is located. If this is not clear enough PM me and I will try to explain better.

10276Choke_Dial_End.jpg


10276Choke_Gage.jpg
 
More pic's

This is the chart I used for the chokes. I don't remember where we got this chart. I notice that the marks for the length marks don't show up in the pictures. Start at the point end and mark in one inch lines to the 2 in. mark and then mark in 1/4 in. lines through the 4 in. pivot area.

Choke_Dimensions.jpg
 
short chamber

I had a Browning 12 made in 1923 and short chambered.the plastic shells failed to eject.I looked gun up and it was 2 9/16.like he said they cut chamber and open ejection port.It was common yrs ago.the mod 12 is worth big money now.more than enuf to get a new 3" gun.:rolleyes5::D
 
Chamber size resolved!

Thanks to you fine gentlemen I now know what I have!!
I followed the advice given here, to turn down a piece of aluminum stock, insert into chamber and scribe. That worked great. I got a measurement of 2.5" so it is safe to assume it is the original 2 9/16 chamber and that it was not modified. I plan on keeping it that way and will go the reloading route. I have been looking at the ballistic products web site for equipment and so far I am gravitating towards the MEC junior or sizemaster. Any major disadvantage with going with the cheaper one? I see there is an adapter for the MECs to accommodate loading 2 1/2" shells. I also ordered a book on 16 gauge shell reloading.


Here are some photos of my M12. It has a few dings and so forth and the pump handle finish does not match the stock (receiver and barrel have same SN) but overall I think it is pretty good for a gun from 1922 that actually got used.

WinchesterM12-16-MOD3.jpg


WinchesterM12-16-MOD1.jpg


WinchesterM12-16-MOD2.jpg


Thanks again for all the help. I may be picking your brains shortly about an AR15 purchase. I have been lusting :drool5: for one.. and time may be of the essence!
 








 
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