A friend of mine picked up a decent 12 gauge Greener with 26" barrels at a local gun show for $400. Apparently, somebody had just sold it to the seller for $250. Odd things happen I guess. Greeners seem to go for somewhat higher prices on Guns International, I've noticed.

It has older British proofs and the flats say "Not for ball," but there is apparently no mention of the chambering. Is there any way to tell without access to a gunsmith?

He sent me this photo:

QUICK way, roll up a 3x5 index card and insert into the chamber, see how far it sides in with out due force.

Second way is to use a chamber gauge

Third way is to check the proof marks more closely and then assume it
is 2 1/2 " chamber or even 2 " chamber


Mike

Not scientific at all, but I have used a fired 2 3/4 shell as a proxy for a chamber gauge on suspected 2 1/2 inch guns. On the guns that I had "tested", that appeared to indicate original 2 1/2 chambering.

You can just stock a tape measure straight in against the wall until it hits the front. Note the measurement as where is comes to the inner lip where the shell brass rests.

Where you really need a gauge is in checking chokes.

- NDG

A chamber gauge does come in pretty handy. Not very expensive.
But in the case of that Greener . . . being marked "not for ball", that would make it a 19th century gun. Too old to have the chamber length stamped as one of the official proofmarks. (That didn't happen until 1925.) But on a gun that old, the gun would almost certainly have left the factory with 2 1/2" chambers . . . although there's always a possibility, on older guns you find here in the States, that they have been lengthened to 2 3/4". 2" wouldn't be possible. The 2" 12 came along later, well into the 20th century.

I just answered this same question in the current "Chamber Length" thread, and explained why I much prefer Miller's oft recommended use of a simple inexpensive 6" machinists scale over 3" x 5" cards, fancy brass tapered chamber gauges, or fired shells. You can read that reply in my post here:

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=538330#Post538330

As you can see from this illustration of a 12 gauge chamber, the length of the chamber is from the breech end to the transition where the forcing cone begins:

Also look for the specific words stamped on the barrel flats,
NITRO PROOF.
If not there then it is a black powder gun & will have the crossed halberds mark in conjunction with the not for ball. Not for ball indicates a black powder proof unless the gun was reproofed & re stamped accordingly.

O.M

That's definitely and older Greener. You need to have the chambers and barrel wall thickness measured properly. Then use loads appropriate for a gun of that vintage. Don't half ass it.

A 6" machinists scale works as reliably as anything I have found. It is repeatable. Been using that method for many years.

Good reminder on having the BWT measured, tho'.

SRH

Whether it is "Nominal" 2½" or 2 3/4" actually has little to do with its age or whether it has only black or smokeless proof as well. Many nominal 2½" British guns, in reality, had either 2 9/16 (65mm) or 2 5/8" (67mm) chambers. What actually determined the chamber length was the gun's intended purpose. Game Guns normally had the short chambers, with Pigeon or waterfowl having longer chambers, up to as long as 3¼" (82.5mm). I recall Nash Buckingham mentioning using a Greener hammer gun of his father's back in the 1880s which had 3¼" chambers.

Larry was correct that the chamber length was not marked at that point. Measuring it will tell you what it has "Now". If the gun weighs in less than
7 lbs the odds are it started life with the shorter chambers even if they are longer now. I don't recall for certain when the 2" chamber was introduced, but don't think it goes back far enough to have been used in a gun stamped "Not For Ball".

I highly recommend the 6" flexible scale method. You cannot accurately "Feel" the start of a normal cone, but you can hold the barrels up to a light source, not overly bright though, & looking through the bore measure to the shadow line keeping the scale along the inner wall & where you can see it.

For those unaccustomed to using these handy little measuring "sticks", there is nothing special about the fact that it is flexible, for measuring chamber lengths. That is just a common way of referring to the little stainless steel measuring scales. Flexibility in it is not a requirement for measuring chamber lengths.

SRH

You are absolutely correct Stan.
I refer to them that way because as long as I am in my everyday clothes & not my "Sunday go-to Meeting" duds I have a 6" flexible Machinist scale stuck in my left front shirt pocket. Actually, the one I am carrying at present is not of Machinist quality, but a General brand I picked up at Home Depot. It's plenty good enough to measure chamber lengths.

When I was actively employed as a Machinist it was always a Starrett with 16R graduations. One side was graduated in 32nds & 64ths with the other side having 50ths & 100rds. This General only has 32nds & 64ths with back side having a decimal equivalent chart. Browne & Sharpe was generally my preferred brand but for some reason, they did not offer this 16R graduation on their scales so I chose the Starrett.

Chamber length is pretty much a moot point in this case. 2 3/4" chamber length would not, I repeat, not, be license to put normal/common OTC loads through it. ON the other hand, 2 1/2" chamber does not preclude the use of properly assembled lighter shot loads at lower velocities with lower chamber pressure in 2 3/4" cases. RST et al probably have loads suitable for this gun.

Consider this gun an elderly gentleman due your respect. 3/4 oz loads work hunkey-dorey in 12 bore guns; I see no reason to believe they would not be a good starting point for an 1150 fps load with 7000 psi chamber pressure.

Just for grins, BV2-OQ7-CC6 = $1031. If there are no unseen/undescribed/unidentified "warts" this looks like a pretty good deal.

DDA

Understand your point, Don. But, since the OP asked for info on how to determine chamber length I (we) was addressing that particular query.

Did you not mean to say, in your last sentence, "they would not be a good starting point" ?

SRH

Does it state a shot load ? 1&1/8oz =2&1/2" .

Funny. Miller carries a 6" machinist scale from the days of his employment. I do too. My employment was lawyering and I needed the scale daily to accurately interpret land surveys and building plans. I still have mine as well, but thankfully use it now for chamber measuring...Geo

I own myself a 16 gauge Greener,the ideal Grouse gun, 26" barrels 5 3/4 lb., made in 1897. I bought it at Safari Outfitters decades and decades ago, and I've shot high brass loads through it without any problem. Except from recoil, it's a light gun and kicks your arm off with heavy loads.

16 gauge Greener

Rocketman,

Have you ever read that series of articles in DGJ in which Sherman Bell tested a large number of Damascus-barrel shotguns with heavy loads and even with overloads?

Thanks to everyone, btw, for the information and replies.

I used the index card method mentioned until I finally got a gauge. I see everyone covered everything so now woohoo! Kudos on getting a greener and getting one at an honest deal. Great job! I would love to see more of it

Do note that upon the introduction of the fold crimp, just prior to WWII the British began experiments with shells longer than the chamber. They were mostly halted by the war but resumed immediately afterward. From that point onward virtually all British 12 gauge shells marked as suitable for 2½" chambered guns were actually put up in a longer hull.

Bell brought this to the attention of a lot of shooters, but to be totally correct in giving credit where credit is due, he neither Discovered it nor Invented it. This fact had been long settled likely before Bell ever pulled his first trigger.

I don't know just how old Bell is but in less than a month I'll be 81 & this was all "Laid to Rest" before I turned 12.

Do note a couple or three things though.
No shell should be fired in a chamber in which the loaded shell has to be pushed into the cone, it is essential there is clearance between the end of the loaded shell & the cone to allow proper opening of the crimp without restriction.
Also no shell longer than the chamber should be fired in a chamber having a step or extremely short cone which lets the end of the shell actually lap into the bore itself. It may or may not burst the chamber but is certain to increase the pressure drastically.
Finally, the longer shell should only be loaded to the pressure level the gun was designed for. This harks back to Rocketman's warning.

It was certainly discussed in British literature, although mostly forgotten on this side of the pond. Gough Thomas' "Gun Book" includes a chapter called "Danger in Case Length", which dates from October 1964. Burrard made reference to the same thing earlier than that. The Thomas article even includes a test he arranged to have run by Ely, firing 2 3/4 shells approved for guns with 2 1/2" chambers in test barrels chambered both 2 1/2" and 2 3/4". Pressure was measured in tons per square inch (standard Brit measurement at that time) at 1" and 6" from the breech, and observed velocity (average over 20 yards, also Brit standard at the time) was also measured. 10 shots were fired in each test barrel. Differences in both pressure and velocity were minimal between the two test barrels.

“Mr. Griffith on Shotgun Patterns”, 1897
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA234

p. 243 “Turnover” – case longer than the chamber
No. 9 2 1/2” case with 1/8” turnover
No. 10 3/8” turnover
No. 11 & No. 12 with 2 3/4” and 3” cases in 2 1/2” chambers = “…patchy patterns, clustering, and frequent balling…” Pattern examples on p.244
p. 245 “balling or clustering”
p. 247 “Summary of patterns”, Field, March 5, 1898
No. 9 - 1/8” turnover better pattern % than 10, 11 & 12

Pressures with 3 Dr. “Schultze” with 1 1/8 oz.
(pressures converted from long tons/sq. inch to psi by Burrard’s formula)
2 1/2” case with 1/8” turnover – 2.13 tons = 6,040 psi
2 1/2” case with 3/8” turnover – 3.03 = 9,060 psi
2 3/4” case in 2 1/2” chamber – 3.22 = 9,700 psi
3” case in 2 1/2” chamber – 3.71 = 11,345 psi

“When long cases are used in short chambers, the paper overlaps the cone and causes greater resistance to passage of the shot and wads. The pressure then goes up considerably, while muzzle velocity and recoil are both increased.”

That is essentially what I said Larry. The British had resolved the matter at least by the end of the 1940s. Burrard essentially made two statements concerning chamber lengths for which he has been accused of issuing conflicting statements. This accusation came purely from the lack of understanding the statements were made at different times & pertained to different circumstances.

In his first statement, he emphatically advised against firing a shell longer than the gun was chambered for. At the time this statement was made it was entirely correct due to two circumstances. First, it was made at a time when shotshells were closed with a fold crimp. A 2 3/4" shell in a 2½" chamber is apt to extend into the cone "Before" firing which should not be done for the reason stated. The second factor was at that point in time the 2 3/4" shells were loaded heavier & for a gun carrying a heavier proof. When the fold crimp was developed & the British gunmakers & ammunition loaders set out to determine if the hull could within safety factors be lengthened without lengthening the chambers it was proved to be feasible. Burrard gave full coverage of this new factor.

I have read both Bell & Thomas' accounts & for whatever reason, neither seemed able to comprehend this & strongly "Implied" it was totally unknown until they brought it to light. This is about as absurd as trying to say that Samuel Colt "Invented" the Revolver. Colt did at least "Improve" the revolver, which is what his original patent stated. All either Thomas or Bell did was to state some facts which had already been proven for at least a decade & a half prior to Thomas' 1964 work & far longer before Bell took it up.

I acquired a copy of Burrard in the 1960s & I knew this before I ever heard of either. I had no problem at all understanding the two different accounts Burrard made nor any problem separating them from one another. They very clearly applied to different circumstances & were written at different points in time, which he made quite clear.

Yes, I have read Bell and others (much like Miller). I am less worried about the barrels than the stock and the barrel-to-action jointing. Barrel failures are very low % probability, but can be catastrophic for the gun and/or shooter. Stock and jointing failures are mostly cumulative over time/shooting cycles, but are costly (maybe too costly for a less expensive gun). There is very sufficient information available, thanks to sites such this, to feed old guns properly.

DDA

A few comments; First this reflects what Burrard originally said & was the truth as stated. These shells would have all be roll crimped/Turnover. The increase in pressure of the 3/8" turnover above the 1/8" turnover shos the pressure rise from an increased crimp strength. The amount of turnover is not stated on the 2 3/4" shell but as not otherwise stated it can I believe be safely taken as the normal 1/8". This allows the end of the unfired shell to enter the cone of the 2½" chamber thus effectively increasing Crimp Strength & even more so on the 3" shell.

What was later proved was that if the normal 2½" load was put in a 2 3/4" case & then closed with a Fold/Pie crimp, the loaded shell was essentially the same length as the 2½" shell closed with a roll crimp. This allowed adequate room for the crimp to open, un-restricted & pressures were then "Normal". In a normal length cone, the slight overlap of the "Fired" shell was not enough to create an undue restriction. This, of course, does not apply with those stepped or unduly short cones in which the fired shell would actually lap into the bore itself. This was all well reported on my Burrard who incidentally made no claims as to having "Discovered" it. He simply reported on the work which had been done by "Professionals" in the ballistics field.

The two main factors thus were The "Load" had to be compatible for the gun it was intended to be fired in (R'Mans Concern) & the Loaded shell must be shorter than the chamber allowing freedom for the crimp to open normally.

Not really that hard to understand.

Miller you have to give to the dOc he does a great job of copy and pasting...

Miller, I know you don't care much for Thomas. But to give him his due, I think you need to reread what he wrote. Concerning Burrard, here is what he had to say. Note that he clearly gives Burrard credit--making clear reference to the longer shells containing a heavier load:

"Burrard leaves no doubt in his readers' minds that the danger in question arises from the inability of the longer case to open up properly in the shorter chamber, and the higher pressure generated by the constriction thus formed. IT CANNOT BE TOO STRONGLY EMPHASIZED THAT IT IS INDEED DANGEROUS, IN GENERAL, TO USE CARTRIDGES WHOSE UNLOADED CASE-LENGTH EXCEEDS THAT OF THE CHAMBERS OF THE GUN."

"But in the particular case cited by Burrard, the main danger arises, not from the constriction when the cartridge is fired, but from the fact that the longer-cased cartridges he had in mind invariably carried heavier loads; and heavier loads in a given gun, USING A GIVEN POWDER, of necessity involve higher pressures. It is, in fact, pressure that causes the danger."
(Emphasis Thomas.)

For those who remained concerned (for whatever reason) about the danger of British shotshells loaded in 2 3/4" hulls but designed for guns with 2 1/2" chambers, Thomas then goes on to publish the Eley test results, which show scarcely any variation in either pressure or velocity, whether the shells were fired in a barrel with 2 1/2" or 2 3/4" chambers.

Larry; Can you point out any part of this post which is Untrue. I just try my best to state facts as they have been revealed.
As to Thomas, I will just say that You & I didn't read the same book, in the one, I read he definitely did not quote Burrard & strongly implied this fact was unknown until "HE" proved it. Burrard made no claim as to having proved this fact, only stated what had been proved by the Expert Ballisticians of the ammunition companies of GB. Actually, a co-worker loaned me his copy, don't at this late stage recall the exact Title or date, but He Said "Burrard Should Have Said & then proceded to say exactly what Burrard did say. When I returned the book it was offered to me at a good discount but I declined He was a very knowledgable person on guns & was unlike me, an "Engineer (Mechanical, not Civil) & also found it worthless & put it up on eBay I believe.
End of discussion on my part, I am not going to be drawn into another long drawn out multi-page discussion with you on anything. Seems most everyone here by now Knows you & how you will twist everything around & When (not IF) you are proved wrong you will even try to take credit for what was proved to you showing you were wrong. BYE

I certainly see nothing in your post which is untrue. So what in there in my post--and in my quote of Thomas--which is untrue? You're saying it in 2019; Thomas said it in 1964; Burrard said it before that . . . and in the quote I produced, straight from "Gough Thomas' Gun Book", chapter entitled "Danger in Case-Length", p. 261, Thomas gives Burrard credit for having said it earlier.

I'm glad you don't want to continue the discussion with me . . .because, just like the last time we got into a discussion on Thomas, you don't have his book to quote from. So you're condemning him based on memory that you cannot confirm. And one reason I have his books is so that I can confirm what he has said (or hasn't said) on various subjects. I'm a few years your junior, and I've learned not to trust my memory concerning something I read a decade or more ago. Nice to have it on my bookshelf, straight from the horse's mouth . . . so to speak.

Nowhere, in anything I've read by Thomas, does he state or even imply that he was the one who proved that it was perfectly safe to fire 2 3/4" shells, loaded to appropriate pressure, in guns with 2 1/2" chambers.