Shotgun, 12 ga, 2 5/8” chambers

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orpington

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Is it okay to fire a 2 3/4” shell in this shotgun? Does the 1/8” difference matter?
 
The length of shot shells is measure before they are crimped. I would not fire a 2 3/4" shell in any chamber that is shorter than that.
Incorrect, the length of a shotgun hull is measured from a FIRED hull. crimp opened.

Older guns with 2-5/8" chambers were typically not designed for some of today's hotter loads. Depending on the gun, a roll-crimped shell should be OK. Standard crimped hulls will open up into the forcing cone area increasing pressures - that can lead to :
A) nothing
B) Accelerated wear of the gun
C) A high pressure scenario with possible damage to gun
D) A catastrophic failure causing destruction of the gun and injury to the shooter.

What gun are you talking about and how old is it?
 
@George P It is the same measurement wether it is a brand new hull that has never been crimped or a once fired hull. At let that is how all of my 410/ shells are.
 
Funny....

My grandfathers' 1928 Model-12 has fired 10's of thousands of 2¾" shells -- by him through 1945, then my father's hunting & military skeet league from `45 through 1970, my own skeet/trap leagues and hunting -- up through 2010 or so....

....only to find out when having it refurbed/bolt recess rebuilt (from slam-firing set-back) in the year of our Lord 2011 -- that it was a (....gosh....) 2⅝" chamber.

....15 sec of honing ....and it's still going strong 7 years shy of the Century mark.
 
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@George P It is the same measurement wether it is a brand new hull that has never been crimped or a once fired hull. At let that is how all of my 410/ shells are.
If you mean by both hulls being opened, then that is correct. Many folks mistakenly think a loaded shell is the length on the box; it isn't and that was my point. A 3" shell will fit in the chamber of a 2/34" chamber but firing it could be disastrous.
 
Funny....

My grandfathers' 1928 Model-12 has fired 10's of thousands of 2¾" shells -- by him through 1945, then my father's hunting & military skeet league from `45 through 1970, my own skeet/trap leagues and hunting -- up through 2010 or so....

....only to find out when having it refurbed/bolt recess rebuilt (from slam-firing set-back) in the year of our Lord 2011 -- that it was a (....gosh....) 2⅝" chamber.

....15 sec of honing ....and it's still going string 7 years out from the Century mark.
As I said in my first post, there were 4 possibilities, with A being nothing.
 
If you mean by both hulls being opened, then that is correct. Many folks mistakenly think a loaded shell is the length on the box; it isn't and that was my point. A 3" shell will fit in the chamber of a 2/34" chamber but firing it could be disastrous.

And that is why I said "before they are crimped"
 


A 1907 Parker side-by-side is a far cry from the Abrams Tank that is the Model-12.
`Agree w/ low pressure 2⅝ shells

.
 
Okay. The concern was being able to shoot vs not being able to shoot do to there being shells other than 2 3/4 not available. I did not realize that 2 5/8” shells were commercially available in this day and age.
 
Just to play devils advocate: Shooting 2 5/8" shells in a 2 3/4 inch chamber will NOT create an overpressure situation. Sherman Bell pressure tested 2 3/4 hulls in both 2 1/2" and 2 5/8" chambers and found that at the extreme end it only raised pressures by 10%, a Winchester AA went from 10,000 PSI to 11,000 PSI and the SAAMI maximum shell pressure is 11,500 PSI, other shells produced less excess. These findings were published in "The Double Gun journal" several years ago. However, the extra recoil produced by the short chambers will damage your stock over time.
 
Funny....

My grandfathers' 1928 Model-12 has fired 10's of thousands of 2¾" shells -- by him through 1945, then my father's hunting & military skeet league from `45 through 1970, my own skeet/trap leagues and hunting -- up through 2010 or so....

....only to find out when having it refurbed/bolt recess rebuilt (from slam-firing set-back) in the year of our Lord 2011 -- that it was a (....gosh....) 2⅝" chamber.

....15 sec of honing ....and it's still going strong 7 years shy of the Century mark.
If that was a 12 gauge, you now have a shotgun with a 3" chamber. Winchester never made 12 gauge model 12s with a 2 5/8 chamber. A mistake many gunsmiths make is taking off the barrel and just measuring that, and not including the headspace ring in the receiver. Many a field grade model 12s out there with 3" chambers because of that.
 
I'm "pretty sure" Wright's knows what they're about:
:) :thumbup:

-----Original Message-----
From: Jill Fox, Wright's Inc. <[email protected]>
To: "moi"
Sent: Wed, Oct 22, 2014 3:31 pm
Subject: M12 Chamber

The chamber length is 2 5/8"
We have your Model 12 on the work board.
Thanks!

--
Jill Fox
Wright's, Inc
(618) 357-8933

1104 S. Main Street
Pinckneyville, IL 62274
 
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1963 before I went on the USAF, I bought a box of Western Auto12 ga purple paper hull shells to go dove hunting with my father's double barrel. First bird was a level right to left crosser; when I fired, I knew I'd hit because I saw the feathers. I looked and looked but couldn't find the bird.

When I broke the action to reload, the front of each shell was shreaded; the "feathers" I saw. I took ot back to the car and got my JC Higgins single shot.

I don't think an old 2 1/2" - 2 5/8" would be as tolerant of plastic as mine was of paper. I wouldn't try it.
 
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Actually the expert genius says plastic is easier because most shells are "skived" and thinned near the mouth for better crimp. Paper is thick all the way.
 
I'm "pretty sure" Wright's knows what they're about:
:) :thumbup:
I wouldn't be. I took the liberty of measuring the chamber of my 1928 production model 12 (Serial no. 527xxx) and found that, with the barrel removed from the action, it does indeed measure 2 5/8. However, there is a ring in the reciever that the bolt headspaces on that makes up part of the chamber, and brings the total length to 2 3/4 inches. Enjoy your new 3" model 12! :thumbup:
 
Since Stu Wright tore everything apart/also replaced the headspace ring as
part of the bolt-stop refurb; -- and -- as Wright was 40 years specialized in the
Model-12 business, I'll have to defer to their finding/judgement on this one.

Incidentally, the Serial is 327,xxx which dates it to 1924. Note also that irrespective
of the everything Model-12 is 2-3/4" lore, those made before 1927 (SN roughly
500,000 or lower) have a 2-5/8" chamber.

Separating the barrel and running a caliper down to where the smooth chamber
starts to transition to constriction (now) measures ~2.62". Add 1/8" for the head-
space ring.--> 2.75" (or so).
 
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Note also that irrespective
of the everything Model-12 is 2-3/4" lore, those made before 1927 (SN roughly
500,000 or lower) have a 2-5/8" chamber.

This has been my experience as well. I had a M12 in 16 gauge, built in 1923 or 24 (can't remember which) and it would constantly jam when shooting "modern" shells. My gunsmith and I figured out that it was made for 2 9/16th shells, and the 2 3/4's I'd been firing out of it were jamming trying to eject. There was no adverse effect on the gun, however. He suggested I either A) enlarge the ejector port ($$$) or B) sell the gun and find a newer one. I wound up trading straight across for my current M12, a 1940 also in 16 gauge. If my memory serves, it's clearly marked on the barrel " 2 3/4" Chamber".

As to the OP's original question: George P nailed it. Unless it's a Damascus/ laminated/ twist steel gun, I'd wager about the worst you'd do to the gun would be to shoot it loose pretty quickly. That's assuming you're not stuffing it with "baby magnum" buckshot/slugs/etc. If I wanted to shoot a few birds with it, it probably wouldn't bother me to stick a couple 1oz trap loads in it and let drive. That's just me, of course. I used to shoot a LC Smith 2 7/8ths 10 gauge with Damascus barrels. Shot lots of factory Winchester paper loads, then loaded them with black powder and shot them some more. I'm still here, and have most of my fingers (lost half of the right middle to a hay baler).

Mac
 
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