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Old April 7, 2012, 01:31 AM   #1
Jack1939
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JP Sauer and Sohn in 2.5" or 2.75"

I was recently given a JP Sauer and Son (or Sohn?) shotgun (possibly a model 75C since it says that under the serial number on the underside of the barrel). The guy I got it from never shot it, it was given to him by an old hunter before he died. I did some research during my ten day waiting period and found that, of the pics I saw on other forums, most said either 12 and then 65 underneath, or 12 and then 70 underneath. The lower number being the length of the chamber in mm (65mm = 2.5"; 70mm = 2.75"). So now I don't know if this thing is chambered for 2.5" or 2.75" shells and I don't want to shoot 2.75" if it is chambered for 2.5"

I know I could try to measure the chamber, but using a cleaning rod or a wood dowel to feel where the chamber ends, and then measuring that... not sure if I want to risk blowing my face off being off by a quarter inch.
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Old April 7, 2012, 05:01 AM   #2
Jim Watson
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This one is marked only (circle) 12.
The default was 65mm; variously given as 2 1/2", 2 9/16", or 2 5/8".
If it doesn't say 70 then it is 65.

The shorter shells for older European guns are available.
Gamebore gottum.

http://www.gamebore.com/page.php?id1=2&id2=4
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Old April 7, 2012, 09:23 AM   #3
PetahW
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The reason is that early guns were chambered when the short ammo was the only ammo in existance.

Once longer ammo started to be manufactured, guns started to be marked to differentiate them, first "70" on those chambered for 2-3/4" ammo, then later "76" in some gauges on those chambered for 3" ammo.

Appropriately low-pressure, but modern, 65mm (2-1/2", 2-9/16") ammo is also currently available from the likes of RST & PolyWad, to keep these old beauties running - AFTER they've been checked out as safe to shoot by a qualified double gunsmith, of course, and not some parts-changer.

.

Last edited by PetahW; April 7, 2012 at 09:28 AM.
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Old April 7, 2012, 09:48 AM   #4
Flatcat
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Great pictures of the stampings, sure would like to see a photo of the whole thing.
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Old April 7, 2012, 09:49 PM   #5
Jack1939
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Thanks for the advice. I saw a jp sauer and sohn on Cabelas that had the chamber expanded from 2.75" to 3.00" anyone know of tools to measure this?

Does anyone make slugs in 2.5"? Could I make them myself? I kinda doubt that there are a lot of recipes for 2.5" slug reloading, but I can get one of those Lee shotshell presses for $40.

Thanks for the links to the 2.5" birdshot but none of those manufacturers seem to make slugs in 2.5"

Here are some more pics

Also, any advise to measure the choke? Just use calipers?
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Old April 7, 2012, 10:25 PM   #6
Jack1939
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Ok, back with more questions already... Should I stick with 2 & 1/4 dram equivalent, or is the 2 & 3/4 dram equivalent safe to use? Looking at ordering some of the polywad and I kinda like the #6 shot "Spred-R" for jackrabbits.
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Old April 8, 2012, 10:04 AM   #7
PetahW
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AFAIK, the chokes are marked into the bottom of each bbl, expressed as a metric measurement - look for a stamping similar to "18.2", "18.3", etc.

.
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Old April 8, 2012, 10:31 AM   #8
Jim Watson
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A nice looking gun, overall.
I THINK it was made between 1903 (Country of origin (Prussia) mark required for US importation as of 1903.) and 1912 (Nitro proof became standard.)
I see no Damascus pattern on the barrels, they are probably steel. Something to look closely at or have checked out.

If so, it ought to handle 2 3/4 DE shells of the correct 2 1/2" length.
I don't know of slugs now available in 2 1/2" shells although Herr Brenneke surely made them in the day. Slugs are usually a disappointment in a double anyhow, the barrels will hardly ever shoot together.

I don't see a conventional European millimeter measurement of choke on the barrel flats. The figure 13 may indicate the chokes are down to the equivalent of a 13 gauge; an older system. The (crown) W proof mark shows that they ARE choked. Shooting on a pattern board is the only sure way to know.
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Old April 8, 2012, 12:50 PM   #9
mapsjanhere
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I found some slugs from S&B on a German website; if anyone imports them to the US, who knows.
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Old April 8, 2012, 01:29 PM   #10
Jim Watson
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If you plan to hunt it a lot, it might pay you to have the chambers lengthened to 2 3/4" for standard US shells. A good gunsmith would check that there was enough barrel thickness before proceeding.

I doubt it will get to be worth a lot of money even if kept original.
It isn't original anyhow, with recoil pad added.
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Old April 8, 2012, 11:06 PM   #11
Jack1939
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Took it out to the range today, not to shoot just to get info on it, and the trap shooting rangemaster is sure it is a 2 & 3/4" chamber, so maybe one of the previous owners already took it to a gunsmith and had the chamber lengthened. He put in a pencil and measured it, also inserted a fired 2 3/4" shell and it fit. I might cut up an old wooden ruler to try to get a measurement, or I migth cut up some fired shells and make my own chamber length gauge to measure it myself.

The left barrel says "Fluid Steel" so it is not a damascus barrel, assuming I understand that correctly.

The left barrel is choked modified (will fit a dime inside but just barely) and the right barrel is modified (fits a dime with a little more wiggle than the other barrel).

Mr Watson: you said "Slugs are usually a disappointment in a double anyhow, the barrels will hardly ever shoot together." Not sure what you mean by that. Do you just mean it is inaccurate or the two barrels will come apart (damage the gun) when you say "will hardly ever shoot together"

I would like to hunt rabbits with it but would also like to be able to shoot a pig, or at least take a shot at a pig, if I see one.
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Old April 8, 2012, 11:10 PM   #12
Jack1939
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P.S. the previous owner never shot it but the owner before that hunted with it into his 80's and I think that it was in the late 1980's that he gave it to the guy who gave it to me before he (the hunter, two owners ago) passed away. Do any of you know if 2 & 1/2" shells were popular in the 1980's? If not I could imagine the hunter could have had the chambers lengthened.
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Old April 9, 2012, 07:37 AM   #13
mapsjanhere
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What Jim was referring to was the tendency of double barrel shotguns to put slugs a foot apart at 50 yards, so you typically need two different points of aim.
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Old April 9, 2012, 01:28 PM   #14
Jim Watson
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Right.
Double shotguns are not normally* "regulated" to deliver slugs to the same point of impact from both barrels like a double express rifle. Many shotguns do not fully overlap shot patterns, for that matter.
A friend wanted to play Big Bwana with slugs in his SKB double. I don't think he ever got both barrels on the target, and sometimes not either one. He liked the feel of it well enough that he bought an express rifle, though.

A slug won't damage a shotgun barrel but it may not hit much out of a double.
I have heard of people putting a sight on a double gun, zeroing it for a slug out of one barrel, and loading the other with buckshot.

*"normally"
There have been shotguns made with sights and regulation for slugs.
My 1939 Stoeger's has an option for the Walther double shotgun to have folding open sights and be set up for Brenneke slugs. $25 for the sights, $7.50 for "Shooting in and targeting both barrels at 60 meters with Brenneke slugs." This on guns running from $100 for the base model up to $290 for one with automatic ejectors and engraving. (Same price range as Browning Superposed or Parker at the time.)

More recently, Bernardelli offered slug model doubles, both SxS and O/U with sights and presumably regulated barrels.

Connecticut Shotgun has made some of their RBL doubles for slugs, but they are dedicated slug-only guns, with rifled barrels to shoot sabot slugs. I am sure they would fire a shotshell but I expect the shot would scatter badly as spun out by the rifling.

Last edited by Jim Watson; April 9, 2012 at 01:39 PM.
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Old April 12, 2012, 12:51 AM   #15
Jack1939
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I wrote to JP Sauer and Son with some pics attached and asked about 2.5" vs. 2.75"

their reply:
I think your shotgun was chambered by the factory for 2.5" shells, but maybe the chambers have been lengthened to 2,75" by a gunsmith. So the best would be to check this by a proofhouse.Another option would be to use cartriges in caliber 12/67,5 which can be used for both 2.5" and 2.75" chambers.

...and I noticed that there is a Lee Loadall II for 67.5mm shells. But it looks like this gun has had the chamber lengthened to 2.75" so I will probably stick to factory loads.

The gun will chamber and eject a fired 2.75" shell. I also cut up two spent shotshells into two cylinders and taped them together. I then stuck it in as far as it would go. When I push it in gently it goes to 2.65", when I jam it in, it will go to ~2.70" or 2.75" so I think it is ok to fire 2.75" shells out of it, right? I think a spent 2.75" shell would not chamber if the gun was chambered for 2.5" and I have not heard of any guns chambered for 2.65"

So, knowing this, do you agree that it is probably safe to shoot 2.75" shells out of it? Thinking about taking it out to pattern it this weekend.
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Old April 12, 2012, 12:18 PM   #16
mapsjanhere
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The question is not if you CAN get a 2.75" shell into it, the question is if you should. The reason they used to have a separate proof for the longer shells was they had more powder. With a 100 year old shotgun, you're playing with fire in using modern heavy loads in it. S&B still makes 12/65 shells.
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Old April 30, 2012, 06:57 PM   #17
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While you are obsessing about the chamber length, a competent smith with a gauge can tell you in 10 seconds exactly what it is

It isn't just the length of the shell, but also the pressures generated by newer ammo. This is an upland gun not a deer rifle and should be used accordingly
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Old April 30, 2012, 08:21 PM   #18
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The use of a fired 2-3/4" shell, which has a flexible mouth, is an unprofessional way to determine chamber length - either measure it properly, of get it done by a professional with the proper tool.

65mm length loaded shotshells haven't been readily available for at least 30 years, until lately, with the current offerings from RST, PolyWad, GameBore, Kent & possibly others.

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