I am looking at a Westley Richards Connaught which a dealer has for sale. The gun is in extremely nice condition - virtually no bluing or case color wear and nearly perfect wood. The barrel wall thicknesses are excellent (minimum 33/1000s). There is, however, a fly in the ointment: the chambers have been lengthened to 2-3/4 inches from 2-1/2 inches and the gun was not resubmitted for proof. The asking price ($7,500) appears to reflect the issue, as other Connaughts I've seen on line go for substantially more. The gun would be my primary grouse and pheasant gun and I'd expect to shoot it with the same low pressure loads I currently use in a Thomas Turner I own that was manufactured in the 1890s.

So, the question: Would you purchase a gun of this quality knowing it was out of proof? I would condition the purchase on inspection by a qualified gunsmith have it inspected before accepting the gun.

All that being said, is this something I should consider or should I just walk away and look for something else?

Thanks.

I have 'no dog in this arena" but- I would ask for provenance as to who/whom did the re-chambering- if the dealer does not know, I'd offer him less for the "alteration" to what passed proof and shoot 2.5" RST 1145 fps loads in it- as I do in my pre-1913 LC Smiths--

If I really like the gun and it had that minimum thickness. I'd do the following making sure there are NO other issues with the gun :
*Negotiate the best deal you can on the gun since it is in fact out of proof.

*Shoot it with the low pressure loads recommended in the above post.

*Enjoy owning a really nice hand made British double at a bargain price.

Jim

Unlike the Brits I have zero problem shooting a gun out of proof IF it still has good wal thickness in the breech area, etc. A really good gunsmith will be able check all these things. A huge number of British guns in this country are "out of proof" and shot regularly with no ill effects. I shoot half a dozen hammerguns with low pressure nitro loads that only have black powder proofs. Same thing. And I feel perfectly safe doing so. The wall thickness in the forward part of the chamber and immediately in front of the forcing cone is especially important for you.

Can't say what you should do, but I wouldn't buy it except for a staggering low price - a price so low I could sell it the next day if I chose to.

It is easy to sell a 2,500$ out of proof BLE, one for 7,500$ I'm not so sure about. If you might sell it in the future, being out of proof could be ab issue. If you are just planning to shoot it, have it checked, then decide.

Hi, the short answer for me is yes. I have a couple Brit guns that have had the chambers let out, but the wall thickness ahead of the let out chambers is in excess of .10 so they are thick enough to handle low pressure loads. They also have thicker than standard .025 WT up the tubes as well. If the barrels are sound, I see no reason not to buy and shoot her.

Joe pretty well hit the nail on the head with regards to this subject.

Best of luck to you!!!

Greg

$7500 is too much money to pay for a gun that is not in proof. It weighs on the resale value and if you want to have it proved you take on all the cost and risk

You could always ship it to England and have it reproofed. I try not to buy out of proof guns, not because they aren't likely safe, but because they will be harder to sell....and most guys buying these English guns know enough to check that stuff out. If it's a great deal I would probably be more inclined to overlook the out of proof business as long as the gun measures up and is safe to shoot.

I saw 2 Connaughts for sale early this year. One was close to new for $8k. I'm not sure $7500 is a good buy with the chambers changed. However, buying a Brit gun out of proof isn't a deal breaker, but it needs to be at the right price.

Ken

I looked at your gun on GI and it is sure a dandy. The seller has the very best reputation and I'm sure would work with you in every way possible to be sure you're comfortable. I believe the gun was actually made by Webley & Scott ( absorbed into WR).

What are the proof marks? At the time this gun was made a lot were chambered 2 3/4" when made.

Joe:

The gun is marked as 2-1/2", so the chambers are definitely lengthened. I think this gun was made by AA Brown & Sons, who were making the Connaughts for Westley Richards and later apparently did some similar guns marked with their own name.

Rem

Buzz pretty much summed it up: Is this a gun you want to own for the rest of your life then pass it on? If the answer is no or I am not sure then I would pass. Just because you are willing to buy it does not mean you will have an easy time if/when you ever want to sell it.

I guess I'm not clear here. Does the price being ask reflect the proof situation? FWIW: AA Brown guns are generally quite lovely. From my perspective this isn't a safety issue, it's a resale issue.

A.A. Brown are still very much in existence and very highly regarded. They do certainly make fine guns in their own name.

Here lies the problem. No I would moy have a problem if it was done by a reputale gunsmith. But when you sell it over here in the US be expected to be asked "Is it in proof?".

A case of Caveat Emptor. One of the benefits is having access to a Proof House to be able to ascertain whether or not it is a good buy. I have bought (there is a legal way around it) quite a few out of proof guns but at a price where it was worth the risk of failure and that after having a good Gunsmith check it over first. I have only ever had one fail and that was put right and re-submitted for a pass. There is usually a good margin of strength built in. Some good bargins can be had this way. It would be interesting to here Smallbore's coments on this as he is in the Trade and will have a lot of experience in this field.

I can recall some time back a heated discussion on this forum about the pro's and con's of an American Proof House. Most were not in favour at that time but clearly there exsists a case for somewhere where guns can be tested properly. Better to fail in a controlled environment than between the hands. Cost of sending it to a Country with a Proof House would add quite a bit to the cost anyway. Lagopus.....

In the UK it would be illegal to offer for sale. You would have to sell it as a stock action and forend.

Well, you are in the USA. So he above does not apply.

You WOULD buy an out of proof US gun because there is no way of telling if it is in proof or not, as it was never proofed in the first place. Do correct me if I got any of that wrong, as I am in no way fully conversant with US gun history - as many of you will happily confirm!

So, if you would buy an out of proof American gun, why not buy an out of proof English gun? Materially, there is no reason to discriminate.

In either case you will still need to check that any work done to it is well done and has not affected it detrimentally.

The fact is, that outside the USA the gun is useless and cannot be sold.

It would need re-proofing first, and that involves cost and risk.

This is why, as a calculated risk, you will pay less in the US market for a British gun which is out of proof.

I'd advise that this is probably not a sensible buy unless you treat it as a gun which you bought cheap and will have to sell cheap when you re-sell.

If you want to use it and it checks out materially and mechanically, and you are not worried about re-sale as you want to keep it for years, it may be away to have a gun you could not otherwise afford.

Advertised wall thickness like other features is not always accurate.

If the wall thickness is verifiable, and all other things are good consider getting it. But you must go into it with you eyes open in terms of the future sales.

I no longer buy guns with an intent to sell them, but I do have to maturely judge whether I am flushing my money down the toilet. If the gun will be a big money loser then only you can answer if it is worth it to you.

Will you get $7,500 worth of value minus what you can sell it for? That value is what I consider gun pleasure rent. If so go for it.

Moreover you must consider the possibility of losing most if not all you have in a gun purchase and you are left with scrap value alone. If you loss tolerance is high then go for it. If like most it is not, then look somewhere else there are many $7,500 guns without issues

Well said. Familiar with the concept of "the greater fool"?

Dig makes an interesting obsvervation


The US made guns go through a manufacturer's proof, but once sold there is no longer a requirement for the gun to be checked for proof. Some of us have the barrels checked out to ensure the gun is safe, but nothing more. We put additional value on an English gun in proof. In the same way, some of us won't pay as much for a US gun with chambers opened and other barrel changes to the gun.

Ken

I would never buy any gun whose chambers had been lengthened unless I could check the wall thickness right at the juncture of the chamber and forcing cone. This is a tricky spot to measure on a double. Was the reamer cocked so as to take more metal from one side? I would want to measure where I could and eye ball the chambers. This is coming from a guy whose left little finger was blown off by a burst barrel. This WR may be perfectly safe but proceed with caution. People who lengthen chambers can have no grasp of barrel stresses and turn a reamer into a deadly weapon. Yeah, it makes a lot of sense to remove metal from the most critical area of the barrel so as to shoot heavier loads. That's the ticket.
nial

"The US made guns go through a manufacturer's proof"
I was not aware of a Federal requirement to proof firearms.

The issue has been discussed as far back as 1895
http://www.la84foundation.org/SportsLibrary/SportingLife/1895/VOL_25_NO_04/SL2504014.pdf

July 27 1895
Call for Government Proof House for Nitro Powder Testing
http://www.la84foundation.org/SportsLibrary/SportingLife/1895/VOL_25_NO_18/SL2518019.pdf

U.S. makers voluntarily test their own guns, no doubt with personal injury lawyers in mind



As I recall we had a long and contentious thread regarding this issue about a year ago.

Yes Drew, I remember the thread well since I was the devil who started it. In this connection, I don't think we have or ever had a problem here in America with newly manufactured guns. I believe the gun companies always have, and still do proof/manufacture their guns to a high level, a level where their guns will safely handle the highest pressure and the most stout loads. Where we do have a problem, however, is in these guns, like the English Westley Richards gun in question here, where there has been some sort of a barrel alteration, such as lengthening the chamber or others like honing bores, poor reaming out of forcing cones, where a gun may or may not be safe and is just sort of passed off to either a knowledgeable gun person or a more ignorant unsuspecting consumer who has no idea what constitutes a safe gun or even what 'in proof' means. I, for one am fond of the British system in terms of the proofing of guns, which takes the guess work out for the unsuspecting.

Here's the real problem with American guns: Back when the changeover was made from short chambers to 2 3/4" as the more or less standard for 12-16-20ga guns, it was not really a problem. Looking at my 1940 Shooter's Bible, I find WAY more factory shells available in the short lengths (2 5/8" for 12ga, 2 9/16" for 16ga, 2 1/2" for 20ga) than I do 2 3/4" shells. But after WWII, by which time American gunmakers were no longer producing short-chambered guns, those shells began to disappear. The common solution when you consulted your local gunsmith: just go ahead and lengthen the chambers.

The problem with that simple solution was that most gunmakers proofed the short-chambered guns to a lower pressure standard than those with 2 3/4" chambers. The difference wasn't huge--around 1,000 psi or so. However, by the time you figure that you're going to get some additional pressure (although again, not a lot) by firing a slightly longer shell in a shorter chamber, you may now be pushing 2,000 psi or so over the service pressure for which the old American short chambered guns were designed. Because most American guns were somewhat overbuilt (at least in comparison to British game guns), this usually was not a problem as far as "catastrophic failures" go. But it may well result in a shortened lifespan for the gun in question, in terms of shooting loose, if fed a regular diet of factory 2 3/4" shells.

That's why, as suggested, it's very wise to check the barrels on any American gun on which the chambers have been altered. (A good guideline: if it wasn't originally stamped 2 3/4", it probably started life with short chambers). And to stick with either low pressure factory loads (like from RST or Brit/Euro ammo makers) or low pressure reloads in guns that have, or originally had, short chambers.

My personal belief is that the 2 3/4" chamber "Marking" did not generally appear on US made guns until after the introduction of the newer progressive burning powder shells as the SuperX/Express etc. t can be generally assumed any US made gun carrying a 2 3/4" mark was designed, built & proofed with these shells in mind. Prior to this, which began in the early 1920's many, many US guns were built with 2 3/4" chambers but unmarked as to length. It can also be safely assumed these guns were not proofed for the heavier load. It is definitely not a guarantee that all unmarked chambers on early US guns started shorter that 2 3/4".
It is also duly noted that all US made guns carrying a 2 3/4 mark do not in fact have chambers which measure a full 2 3/4" long. In fact until only fairly recent times SAAMI specs for a 12 auge 2 3/4" chambered gun listed minimum dimensions as slightly under 2 5/8" & a minimum cone of 4/10"/.400 (5° per side). Such guns were designed, built & proofed for "ALL" 2 3/4" shells available at the time.

Thanks for your imput Diggory.

Oddly, within ten minutes of posting yesterday I was offered a Stensby of Manchester hammer gun. One barrel in proof and the other 1 thou. out. It would have required too much other cosmetic work to make it viable. A plain back action sort.

The way round it, as Dig mentions, is to buy the stock and action and have the barrels sent to a Registered Firearms Dealer for repair. Marry the lot together and have the gun sorted and re-proofed. Dig is a RFD so can legally take them in without breaking the law. I have to skirt around it by the above method but it is often a way of getting a bargin and making a small profit. This has to be weighed against the risk though. Lagopus.....

I have never had a problem in buying out of proof (hammer) guns privately. I was under the impression that only the vendor was breaking the rules by offering them for sale - have I got this screwed up ?

I and I suspect others here would be interested in the specifics in regard to your unfortunate burst barrel experience.
Jim

Lagopus mentions buying a gun one thousandth out of proof, suggesting that it may have been drilled out as much as ten thousandths. What is worse, a quarter of an inch at the forcing cone or ten thousandths from the forcing cone to the choke? To take metal out of a barrel to shoot more powerful shells makes no sense to me, especially after Sherman Bell's testing shows us that a quarter inch more shell doesn't change pressure enough to worry about. A 2 3/4" chamber in a gun proved for 2 1/2" shells shows me that the gun was not only owned by an idiot at one time, it was also worked on by an idiot. I, personally would not want to own it unless it was really underpriced.

The problem, eightbore, is that your typical US factory 2 3/4" load may very well generate a higher pressure to start with than the loads for which an American short-chambered gun was designed. (It's not the length of the hull as much as it is what's in it.) By the time you add in the extra pressure that comes as a result of a slightly longer hull in a slightly shorter chamber--and in at least one or two of Bell's tests, the increase was around or over 1,000 psi--then you may be putting your foot into dangerous water. I don't worry about low pressure reloads in 2 3/4" hulls being fired in short chambers. But with reloads, especially in 12ga, we can work for pressures that are well below the service pressure for which the gun was designed--thus leaving enough safety margin to cover any increase in pressure resulting from the longer hull. Both Greener and Thomas stress, however, that firing the higher pressure 2 3/4" factory loads in short chambers is a bad idea.

You could ship it to Briley and have it rechambered to 2 1/2.
danc

If you re-chamber it to 2 1/2" it would still be out of proof as the proof becomes invalid when the barrels are materially altered - this includes chamber liners. I re-proof guns routinely - we generally re-proof all guns for 70mm now, the proof pressure are the same for 65mm and 70mm and lengthening the chambers makes the options a bit easier, especially for those travelling.

Dig, somewhat confused by the above. As I understand it, 65mm guns can only be standard proof (the old 850 bars). 70mm guns can be standard proof, but you can also request magnum (now Superior) proof, can you not? And if the gun is standard proof, even if 70mm, the service pressure is lower (10,730 psi) than SAAMI standard service pressure (11,500 psi) here in the States. Thus, would not a 70mm standard proof gun still have issues with American factory 2 3/4" shells?

Diggory, can a 2 1/2" chambered gun be submitted for 70MM proof? Regardless of what Larry is trying to say, drilling a perfectly safe 2 1/2" gun out to 2 3/4" is just money out the window.

At re-proof, the chambers are measured. If they are 2 1/2", they will be proofed and stamped 65mm STD. If you lengthen the chambers to 2 3/4", they will be re-proofed and stamped 70mm STD.

65mm standard proof and 70mm standard proof are the same pressure. 70mm Superior proof is generally only used in very heavy 'magnum' wild-fowling guns.

I am not familiar enough with American ammunition to be clear on what you can buy which is suitable.

All 70mm ammo here is OK for use in standard proof guns with 70mm chambers unless marked 'magnum;.

That does not mean that you won't wear out a gun and or yourself if you choose to shot punchy, heavy loads through a light gun. Just because the chamber has been tested to withstand a certain load does not mean it will be a good choice for regular use in your gun. You still need to exercise common sense when choosing a load.

Small bore,
Can you solve this conundrum?
I have always had a special interest in early British hammer guns. Guns made pre 1868 were proof tested and proof marked to different standards to post 1868 guns.
For example a pre 1868 gun 12 bore stamped 13 G at proof could have a legal bore size in the range .700-.728 diameter.
Post 1868 the bore size were identified by diameter and stamped on the barrel as follows:
13 .710-.719
13/1 .719-.728
12 .729-.740
My 12G Daw of circa 1861,proof stamped 13 G has bore size of .725
Is this gun still in B.P. proof Bearing in mind that it was proof tested under the rules applicable prior to 1868?

Small bore, it would be a great help for some of us if you could provide us with the complete London rules of proof 1855-1868, along with bore diameters for each gauge marking. Please.

Dig's book
http://books.google.com/books?id=lvBk8df8PjUC&pg=PA139&lpg

Possibly he would be kind enough to reproduce the chart here.

Maybe Dave would make this wise advise a permanent sticky

"You still need to exercise common sense when choosing a load."

European cartridges have to be proof tested also (random samples from a batch) to see that they fall within safe limits compatable with the pressures for which the gun was proofed. Such ammo boxes will be marked with the CIP logo. Certainly the older American made Winchester AA cartridges imported to Britain and the Remington RXP's in the 1970's were found to be well over the safe limits for 2 3/4" chambered English guns. American ammo is quite punchy; or at least was then. Even if you have an English 2 3/4" chambered gun I would be cautious about using non-CIP ammunition. Lagopus.....

I have no objection to anyone posting my at-a-glance guide to dating guns by proof mark. However, Nigel Brown does a more comprehensive job in the back of British Gunmakers - he had more space!

Basically, as long as the bore is less than 10 thou bigger than it was stamped at the time it was proved, (and is not materially weakened by deep pits, or altered by lengthened chambers, screw-in chokes etc) it is in proof.

Nialmac has very valid point about reamers being deadly weapons in the hands of the unskilled.

It is not only a matter of in or out of proof. There are deeper considerations of design. Pat Whatley, formerly CEO of Webley and Scott brought this to my attention in 1984. I had asked for a SXS to be built along lines of what later turned out as the RBL. Mister Whatley's observation was that the forgings used by W&C. Scott at that time where not substantial enough for my design. Moving the forcing cone forward brings on changes in the stress development in the action as a whole.

Having measure some deepened chambers I found that the wall thickness at the chamber cone juncture in some came down to an alarming 64 thou, in most was around 85 thou and the recommended thickness for modern steel barrels is around 110 thou*. Most of the chambering reamers used for these "alterations" were Spanish made with no rim stop. It all depended on the "judgement" of the person doing the reaming. And though it would have been s simple matter to measure existing diameters and thickness and calculate the metal that would be left, this was obviously not done. Or it might have been done and the client never told, after all he was the one insisting on the job being done.

* Recommended not oly for current safety but also taking into account future rebluing, honing and general wear and tear.

So buyer beware still is the best advice in all gun transactions. Buy it if it has been inspected by a very well trained gunsmith, if he deems the metal not too weak or thin, if you get it for less not more money, if you shoot only low pressure shells, if you are not concerned about full recovery of your money, if you never intend to take to a place where proof laws are enforced and hope to sell it there and if you can not find another one in proof. Sounds like a seven if gun to me.

Real problem is you need to know who worked on the barrels and how much has been done to them. Best to not have the chambers let out because it gives you a false sense that you can shoot American factory shells in it. It was not designed for them or the high pressure that they come with. Worse what it you lend it to some who loads max. loads and the pressure causes a major failure with damage to the gun and the shooter. Who sues who then.

Lagopus, American cartridges are also proof-tested. The problem is that major American ammo makers don't worry about pressure as long as it does not exceed the 11,500 psi SAAMI standard. Nor do they indicate pressure on the cartridge boxes. That's why both Burrard and Thomas explained that the real issue was not the length of the fired hull, but rather the load in question. Burrard wrote: "It is true that all American fully crimped cartridges loaded with but 1 1/8 ounce of shot develop pressures which are considerably higher than those given by the corresponding British cartridges, but this is due to the relatively higher powder charge adopted by the Americans rather than to their use of a 2 3/4" case." That statement is no longer true if you include companies such as RST and Polywad, that specialize in light, low pressure loads. However, it is true enough reference the offerings from our major ammo makers that it would not be wise, IMO, to shoot most American factory loads in British standard proof guns, even if they have 70mm chambers--unless you know for sure that the pressure for the shells in question falls within the lower CIP standards.

I have found that rarely is there a question that has not been asked before. So here goes. When you take a 2 1/2" chamber and lengthen it 1/4 of an inch to 2 3/4". How much barrel thickness do you lose, in comparison to the same make and model and gauge that is factory chambered for 2 3/4" shells? I measure a few 20 gauge barrels and the outside taper of the barrels drops about .020 to .025 in 1/4 inch. I believe this would mean that the barrel thickness from the taper alone would lose about .010 to .012. Then again the inside diameter tapers down a little smaller going from a chamber diameter to the forcing cone and then down to the bore size. On a Parker 20 gauge it goes from .698 ( Chamber) to .685 (Cone) to .615 bore. I am using Chamber and barrel bore measurements as listed in the Parker story page 519. I am guessing if Chamber and bore diameters stayed the same with later guns that the only thing Parker could possibly do if lengthening the chambers 1/4" is this critical, would be to make the barrel blanks larger or change the outside taper. I am sure I must be over looking something.

That's about how I was trying to put it Larry. I do know that some U.S. ammo imported here in the 70's gave rise to quite a bit of concern. I still have quite a few boxes of Winchester Upland from that period. I'm quite happy to use them in Spanish guns proved to 900kgs. (our old 2 3/4" magnum proof equivalent) but not in 2 3/4" British proofed guns. Our Winchester shotgun stuff that we get now comes from Italy and is CIP approved. Lagopus.....

Lagopus, you folks on that side of the pond are fortunate in that respect. If ammo carries the CIP stamp, you're in good shape to shoot it in any standard proof gun. Of course we can do the same over here with CIP-approved ammo. But far too many people continue to believe that any gun with a 2 3/4" chamber can handle any 2 3/4" shell.

Larry are the pressures you are quoting from SAAMI and CIP LUP or psi?

Mike, those are psi. In England, until fairly recently, they were still using the old lead crusher method, and the pressure figures they used--since they were taken with crushers--were LUP. But my CIP figure is straight from Roger Hancox, the Birmingham proofmaster. He converted the old LUP figure (which was 650 bars service pressure) to the psi equivalent.

http://www.onlineconversion.com/pressure.htm
650 Bars = 4.21 (Long Tons / Square inch)

http://www.doublegunshop.com/forums/ubbt...age=4#Post61404
Scroll down to 2-Pipers's post.



So, using "P=1.5L(tons)-.5tons"

4.21 LUP (Long Tons/Square Inch) = 5.815 Piezo (Long Tons/Square Inch)

Using 2240 pounds per long ton:


5.815 Piezo (Long Tons/Square In Foot) = 13,026 Piezo PSI

I went wrong somewhere. Perhaps 2-piper will pipe in and tell me where I went wrong.

650 BAR = 9427 PSI. If that's LUP then I don't think one needs to worry about shooting US shells in the thing. Of course they may have changed the system of measuring when the BAR's were introduced. I did caution that formula was good only for those old British pressures measured in Tons per Sq In. Note that if you run the formula for 3 tons you get a PSI of 8960 or about 618 BAR. A 3¼ ton LUP converts to 9800 PSI while a 3½ ton one goes to 10640. 3 3/4 tons = to 11,480 or about the same as our SAAMI spec. This is getting pretty high. I seriously doubt that any game gun was meant for over 13K PSI for a service load.

FWIW:

The Rottweil shotshell brochure mentions the CIP service pressures for modern CIP standard proof cartridges in bars:

12 gauge: 740 bars

16 gauge: 780 bars

20 gauge: 820 bars

All figures in "piezo-electric"!

Here is a link (hope it works). The info is on page 7 of the brochure under "Playing IT Safe".

Rottweil Shotshell Brochure

Rottweil, as you all know is one of the most respected cartridge makers and make CIP tested cartridges.

All the best

Skeeterbd

Skeeter, the 740 bars 12ga service pressure is 650 bars crusher converted to the transducer measurement. Likewise, 850 bars proof (crusher) is 960 bars transducer. Once you get the transducer measurement, then you can multiply x 14.5 to get psi.

Miller, the old magnum proof (current superior proof) guns have a service pressure of 1050 bars transducer; 1370 bars proof. I don't think those guns are actually meant for 13K plus loads, but they are proofed to that level. The service pressure figure Roger Hancox gives for one of the 850 bars guns: 10,730 psi. (13,920 psi proof.) From those figures, it's obvious that there's a lot more margin between service pressure and proof pressure under SAAMI rules than there is under CIP rules.

According to my "Convert" program the conversion for BAR's to PSI rounded to 3 decimal places is 14.504. Using this factor the above pressure convert respectfully to 740B = 10,733PSI; 780B = 11,313 & 820B = 11,893. It is also noted that "Magnum" cartridges in all three sizes are given as 1050 BAR or 15,229 PSI & reguire guns of special proof for use.

Right. Once the changeover was made from the old tons proofmarks to bars, in the late 80's, there were only two proof levels for British doubles: Standard (850 bars) and Magnum (1200 bars)--for 12ga guns. That's basically the same system still used today, although the guns are now marked with STD under a crown or SUP under 2 crowns. Bars no longer marked. There's also a special proof process for steel shot, with the guns being marked with a fleur de lys and "steel shot". But as far as I can tell, the only difference between the steel shot proof and the superior proof is that 3 steel shot loads are fired in each barrel. But there are also CIP-approved steel shot loads (relatively low velocity and limited to smaller pellets) for guns--even at the standard proof level--that have not passed the steel shot proof.

Proofing is an interesting situation. I am reminded of a Sako rifle brought to me by a new buyer. He was wondering why he could NOT chamber a round in it. It had been proofed but the chamber had NEVER BEEN CUT! As it turns out, Sako only has to actually proof 3 of every 100 guns. Hmmm. At one time I worked for a big box store and problem guns were brought to me. In 6 months, I had 6 Rem 700 short magnums returned with all exhibiting overpressure situations with FACTORY AMMO! Most could not extract the round. The guns were sent to Remington and all returned either fixed or with replacement guns. There was never an explanation. Hmmm. The fat cases with little angle are a promise of over pressure.
Sherman Bells experiment was very interesting with rather little pressure variation between 2 1/2" and even 3" (600 psi as I remember). Also the barrels of Damascus and regular steel bursting finally at 29500-30,500 psi was also very interesting. In the case of doubles, I think there is little danger about which to worry but lots of value about which to worry.

Yes, a Gunsmith friend had a Spanish AyA brought in that had proof marks but the chamber rims had never been cut. Therefore that gun had never had a proof charge fired through it. I can assure you that ALL British guns go through the Proof House if correctly marked. It seems some countries have a slightly different view sometimes. Lagopus.....

Again FWIW!

Please note this is from another website and should not be treated as the final word!


CIP Pressure Chart

Re soft iron shot the charts on page 17-18 of the 2013-14 Rottweil Shotshell Brochure is perhaps of interest.

[url=rws-munition.de/fileadmin/rws/bilder/Service/Download-Bereich/Englisch/issuu_englisch/Rottweil_Shotshells_englisch_2013.pdf][/url]

I think L.Brown was saying the same thing.

All the best

Skeeterbd

A bit more increase than you remember, Pete. Looking back at Bell's article: one 3" load increased breech pressure over 1400 psi when fired in a 2 1/2" chamber. 2 3/4" loads in the short chamber showed pressure jumps as high as 1216 psi. Others at 909, 891 and 787 psi. Others lower than that. Of course the problem would likely come if it were American 2 3/4" factory ammo, which--if at the SAAMI average max service pressure of 11,500 psi--is already about 800 psi over the service pressure for a CIP "standard proof" gun. By the time you add the potential increase for the longer hull in a short chamber, you could be in the vicinity of 2,000 psi over standard service pressure. Not a problem for reloaders, who can hold down the pressure to begin with. I work up a 7300 psi 1 1/8 oz pheasant load in a 2 3/4" Gold Medal hull and don't worry about pressure at all--although I would not want to shoot a round of trap with those in my sub-6 1/4# Brit game gun!

This has me confused as I am not a gunsmith...I have a Grant side lever which had new barrels made by Boss in 1904... Here is what the ledger says about the new barrels....that they have been made for 2 3/4 chambered " American " casings. But this is 1904.... Also for 6 loads.....the proof marks on the new barrel do not show 2 3/4.... I have been on occasion shooting factory target loads at the skeet range of 2 3/4..... Am I walking the line here because of the dates.?..


Boss ledger:

Note that at this point in time chamber length was not marked per se. However the 1¼ oz maximum load for the shot does indeed indicate a 2 3/4 inch chamber. The nominal 2½" chambered game guns carried a 1 1/8 oz maximum mark.

As with many of these topics, nothing is quite so cut and dried.
The ledger shows that the chambers were 2 3/4" and I would take that as fact but the 1 1/4oz. Max. does not necessarily mean that all chambers with that proof were 2 3/4". There are many British guns from that time with 1 1/4oz. proofs which have 2 1/2" chambers and 2 3/4" chambers would have been unusual.
Also, supposedly, guns with 2 3/4" chambers should have the "LC" designation under the 12 in the diamond indicating a "Long Chamber" but I rarely seem to see that mark, even on guns with original 2 3/4" chambers.

I believe the LC mark is only for chambers longer than 2 3/4".

Pressures for American factory loads were increased in the 20's, when Western's then-new Super X load appeared. SAAMI did not exist until the 20's, but generally speaking, American factory loads were lower pressure prior to that time. I've read from one source that the Super X increased service pressure by about 1,000 psi. In any case, I would not shoot modern American factory loads (other than RST's etc) in a Grant that's over a century old.

Larry is right, the LC mark did not begin with chambers less than 3" in length. W W Greener definitely speaks of 2 3/4" shells being in common use for both Pigeon & Wildfowl guns. The common proof for a 2½" game gun was for 1 1/8oz, that for the 2 3/4" guns 1¼ oz. A 2½" chambered gun carrying a 1¼ oz [roof would have been by special request "Only" & would be the much more "UNcommon" proof.

Thanks again for that information... I have been shooting 2 3/4 at one ounce or 3/4 ounce loads...but you are sure I should abandon that and shoot the RST...RST makes 2 3/4 as well...I will think about all this...here is the history for the Grant which has me wondering further...the chambers do measure out just right at 2 3/4. It seems the orginal owner was also the guy who had the work done at Boss...so I do not know if The later Jones owner did anything to it even though it states the guns stayed together till the 1940's.

Condor;
I believe the 2 3/4" chambered guns of this era carried the equivelent of a 3¼ ton proof. This would translate to about 9800 PSI. It is noted this is less than SAAMI spec shells & is around 1,000 PSI below modern day CIP "Standard" which was listed as 740 BAR (about 10,730 PSI).
Personally I would be much more concerned with the increased pounding on the gun overall from heavy loads than the actual pressure increase.

Ok...understood...thanks again...

That's the standard 2 3/4" proof mark applied between 1896 and 1904; so correct date for your gun. This was later translated to the 3 1/4 Tons per Square inch proof mark. Not nessessarily for American cartridges, just the British mark for 2 3/4" chambered guns in that period. Lagopus.....

Right, I stand corrected! This explains why I never see it...
Perhaps it is my own cognitive bias but I seem to observe that most guns from this era bearing the 1 1/4oz. proof marks are 2 1/2" guns and not 2 3/4".

Lagopus is correct. LC is a 3" chambering and the 1 1/4oz stamp shows a 2 3/4" chambering for the heavier cartridge.

Wirnsberger shows 12/LC defined as chamber length " over " 3 inches. Is he wrong ?

I have a Midland Gun Co. gun with 3 1/4 inch chambers and the barrels are so marked: " For 3 1/4" Paper Cases". Maybe LC refers to these!

All the best

Skeeterbd

Seems to be some dispute on the LC. Baron Engelhardt, who's usually regarded as pretty authoritative on British proofmarks up to at least the 1925 changes, says over 3". Lee Kennett, who basically updated Engelhardt's work to incorporate the changes made in the 1950's, says 3" or longer.

There are some low pressure loads listed on imrpowder.com in the target section. I remember one that was RXP hulls, AA wads, 1150 fps, 1 0z at about 4200 psi. That would likely make the case length thing superfluous. Some of these powders can produce puff loads if the ammo has been in very cold conditions for some time.
Accurately comparing old proofs and pressures is a tricky subject with different standards, different measuring equipment, perhaps even different places measured complicating the situation. Wear and tear on the barrels may not be as important as wear and tear on the stock. Higher pressure means greater force per firing on the stock. On an old gun there may be shrinkage on the wood/metal interface, softer wood due to improper oils or water damage, loose screws, etc. Cracks can more easily occur on a great old stock.
Pressures will also vary due to thick paper vs thin plastic hulls.

After reading this thread over several times and even searching back to a lengthy discussion here back, I think 2007, I am understanding the issue. My last question is that with US loads at around the same velocities , I.e. 1145 + or minus, and the 9800 pressure mentioned, one thing I am not clear on and may have missed it herein is with factory US loads at, 1 1/8....... 1......... And 3/4......is it correct that all three, give or take will produce the same pressures? I know with the 3/4 factory load I feel less felt recoil and am perhaps assuming wrong that it is better for the old gun than the 1 1/8... So with whatever load weight, I am still over the 9800 pressure limit of the proof of the 1 1/4 limit even with the 2 3/4 chambers....so maybe I do not understand. As already mentioned the US factory loads give velocity, or drams....but no pressure disclosure.

Ps..it is just that trying to put it all together , especially with that 2007 thread, is like Stephen Hawkings String theory, Quantum Mechanics and black holes...so I am just trying understand the pressure in the three common loads and if it makes any difference as to the intergrety of the gun, both as to danger and or beating the gun up....I did get various opinions here...one do not use, use but do not worry about pressure be more concerned with beating the gun up....hope you can still have patience with this dummy.

Condor, don't feel bad. It's a very complicated subject. Pressure does not relate directly to either velocity or shot charge. But velocity and shot charge are the most important components of recoil, and reducing recoil is a very good thing for old guns to avoid cracking old and maybe oil-soaked stocks.

It's my understanding that the major American ammo makers don't put pressure on shotshell boxes because they sometimes change from one powder to another. They strive for 2 things: Constant velocity, and pressure within the 11,500 psi SAAMI limit (for 12's). They don't really care about pressure because they assume you're shooting a gun that meets SAAMI standards. European shotshells, on the other hand, have to conform to CIP standards--which means that if they're for standard proof guns, the pressure ceiling is about 800 psi lower vs SAAMI. In this country, RST and Polywad offer low pressure loads, and Kent (Gamebore) and B&P shells that meet European standards are also available.

With older guns, you want to hold down both pressure and recoil. One reason American factory loads--especially some of the very fast hunting loads--are bad for vintage guns is, even if there's not a pressure issue, the velocity results in a lot of recoil. You don't need 14-1500 fps in a lead shot load to kill pheasants anyhow. 1200 fps or so has worked quite well for a very long time, and the last few I've cleaned haven't been wearing Kevlar.

L. brown, thanks very much , so as being my teacher so to speak , if I say this, with the Grant mentioned above, with the 2 3/4 chambers and 1 1/4 max loads proofed in England , even though stating for "American " casings, would be for loads current at the time in 1907. Since those have changed with SAAMI....any of the three US Target loads mentioned in my post above, or for the sake of argument, similar Game loads, all with generally the same velocities at sub 1200 fPS, would STILL be over the pressure limits conceived with the Grant Boss barrels were made(CIP). But, those lower velocities might still be ok to use as stated since one does not need higher anyway...which I agree for field hunting...but since velocity or shot charge does not necessarily relate to pressure....I should still use a shell like RST......for pressure and recoil.....and could use the lower US Factory load of a 1 once or 3/4 load only for the benefits of low recoil, but still must face up to the higher pressure issue not intended when the gun or barrels were made....would you give me a passing grade on what I just wrote?

One of the nice things about most reloading info is that it DOES give pressure info although it is current pressure measured with current equipment. Some manufacturers do sell low pressure rounds but remember that most trap/skeet loads while low velocity and light shot charges use cheap powder which is rather high pressure. Reloading still gives you the most control over pressure.

Just at a quick glance in an old Alliant handloaders guide I find a 12ga 2 3/4" load giving 1¼ oz of shot 1330 fps velocity @ a pressure of 9,500 PSI.
From the same hull but different powder, wad & primer 1 oz of shot is given 1200 Fps @ a pressure of 10,600 PSI. Thus 80% of the shot weight is given 90% of the velocity at an 11.5% increase in pressure. The heavier load in spite of its lower pressure will give you more recoil & put more force into the stock.
It is somewhat debatable as to just which parts of the gun the lighter load with higher pressure will actually be harder on.

Unfortunately, I do not reload...but I have had it all wrong...you can tell I felt the lighter load, the 1 ounce or 3/4 ounce , with the light recoil would have ALSO been less pressure...I had it all backward......the debatable issue of what's best is RST...as has been stated.....it is a non sequitur to me that . If I used 1 1 /8 load , the pressure would be less than the 7/8 ( I was stating 3/4 before...Iwas wrong, I meant 7/8ths)' but the recoil greater!.....with ample wall thickness I can use any shot...but would be better with the Lighter load for less recoil although debatable depending on the powder. I use RST on my 2 1/2 guns...but with the Grant as an example I am using:

1.BP..Competition One...2 3/4, G. 24 , 7/8 once ( do not know pressure)

2. Federal Ultra, 2 3/4, 1 oz., 1180 fPS ( do not know pressure)

...thinking these would be fine...why, less recoil on the old Gun...AND wrongly thinking less pressure....but as stated by one poster I should not worry that much about pressure and be more concerned with the recoil on that Gun.

3. federal Target load, 2 3/4 dram, 1 1/8 oz shot..1145 fPS....I would NOT use this on the Grant

Basically , This all the info on the boxes.

Any of these could be 8, 9, or 7 1/2 target shot size
For birds, I would simply use RST and as stated should not even worry about all this but use the RST...I guess I may have to start reloading

Sorry, I am being repetitive.....but it took all this just to find out I had it " generally" backward.... I just could not work it though all the posts and mathematics.

Condor, to be completely on the safe side, you don't want to use ANY American factory load in a 2 3/4" British double unless that double has passed magnum/superior proof--and your gun has not. Pressures generated, even by "light" loads (in terms of shot weight) and even with moderate velocities, can still approach the 11,500 psi SAAMI pressure ceiling. Anything that reduces recoil--lighter shot charge, lower velocity--is a better choice for vintage guns. But it doesn't get you off the pressure hook.

One reason many of us reload is because we can produce low pressure loads with light shot charges at moderate velocity, all of which are good for vintage guns. If you don't do that and you want to minimize risk to your vintage gun, then you're pretty much stuck with shooting factory low pressure loads from RST and others.

Thanks L. Brown, that is as straight forward as one can get and gives the layman the " yes" or " no" answer with the questions I had in one brief paragraph addressing all the issues....perfect for me....thank you again and to the the others who posted advise as well. The effort by all who explained reminded me of a T. R. Quote..." Nobody cares how much you know, until they know how much you care."

Thank you to all who participated in the very informative discussion about chamber lengths and proof markings and the very important discussion about manufactured shells and their ballistic properties.
The better we understand what we put in our guns the better we can take care of them and avoid costly and exasperating damage

Justin, that's what this place is all about. I think all of us who've been around pretty much since the beginning have learned a lot. In many cases, we're passing on what we picked up from participants who are no longer with us, like Larry Barnes, Bill Wise, and too many others.

I recently purchased an 1894 vintage Greener Emperor. The gun has only one proofmark on each barrel, which is the provisional black powder proof. Graham Greener figures the gun was kept in-house as a platform for development of numerous single trigger mechanisms. The barrels are immaculate and measure .045" at 15" from the breech. I use very light RST loads for ruffed grouse. The lack of other proofmarks probably had a significant bearing on the low price I paid for the gun.

Condor;
Realize that a light load does not necessarily have a higher pressure than a heavy one, its just that the actual shot weight &/or velocity does not guarantee a certain pressure level. The thing to remember is when we talk about the pressure we are generally talking about the "Maximum" chamber pressure. There is of course pressure behind the wads all the way down the barrel. Once ignited the pressure rises very rapidly to its maximum within the chamber itself, then begins to fall as the shot moves down the barrel. With either a heavier load of shot or a higher velocity or both, the total average pressure over the full length of the barrel will be "Greater", But the "Maximum" may not be. The burn rate of the powder plays an important role in this. The two example I cited from Alliant the heavy load was with Blue Dot, a slow progressive burning powder, while the light load used Red Dot, a very quick burning powder. Thus while it did peak very quickly to a higher pressure it would have also fallen quite fast & had a lower pressure for the rest of the travel down the barrel. Too many time we tend to think of pressure only in terms of that maximum peak & totally ignore the rest of it. That peak of course is important, but we also need the "Rest of the Story" as Paul Harvey used to say.

Miller... That is also a great summary....the types of powders and burn rates I now see are key...this was mentioned before in other threads but with formulas that made my eyes cross...thanks...I have copied this thread to save.

Pressure curves do vary depending on powder, shot charge, etc. However, they all--including even black powder--have one characteristic in common: They all drop very rapidly once the shot charge is outside the chamber. Unless your gun has a pretty thin spot in the barrel somewhere not very far in front of the chamber--and that's one reason we check barrel wall thickness--it's highly unlikely that pressure will result in a burst anywhere further down the barrel.

I saw a pressure curve for a 20 ga load using Green Dot that indicated peak pressure @ around 0.5 Milliseconds after ignition. The example used was to show the impact on pressure of various crimp lengths & wads but basically showed peak pressure @ 0.5 milliseconds with variance of about .0075 milliseconds depending on the changes made (obviously changes in pressure resulted also but I don't remember what they were & it's not relevant).

Does anyone know how 0.5 Milliseconds translates to inches down the bbl for peak pressure?

To ask the question another way, does peak pressure actually occur in the chamber or is it farther down the bbl like in the forcing cone area?

There was once a poster here who was doing experimental work and trying to sell the results to the government. I forget his name. I think this was in the original format days MANY years ago. He has devised a duplex load (according to him) which got 8000 fps in a Garand and 10,000 fps in a Browning 50. The theory was to keep a nearly constant pressure until the bullet (or pleshette) leaves the barrel. This required a bull barrel as thick as the chamber area. It was a mixture of a $1200 powder and a $32,000 powder. The trick was for the pressure to increase as the volume increased behind the projectile resulting in a constant pressure behind the projectile. That way, the chamber pressure was as constant as possible. Neat idea it would make a Garand or Browning 50 a tank killer. Many it was real, maybe it was hooey, but the idea was interesting.

On every pressure curve I've seen--those in which pressure is measured over distance rather than over time--it happens in the chamber, right around the 1" mark.

I have not seen anything positive to show that it has changed, but Burrard stated the reason for placing the gauge at 1 inch from the breech was to ensure the maximum pressure would always be caught. Thus even using the fast powders of the day the max would not be reached closer than 1 inch, but it would occur very shortly thereafter. Even using the most progressive burning powders suitable for shotgun use has not given a very large shift of the point where the peak is reached.

Larry,

Thanks, that is the info I wanted & I also got similar data from a graph Drew Hause posted.

BTW I was Tim Wolf's loader for the flurry @ the Great Northern Shoot. Tim owes all his success in his flurry score to my loading abilities. He even had the nerve to take a $ side bet from me on the flurry but I don't think he gave his best when loading for me.

Brittany Man, I think Tim probably shot the best score of the shoot, compared to others just using one gun and one loader. Obviously, you did a fine job loading. You'd be more than welcome to come to Scotland in December and load for me . . . but you'd have to pay your own expenses.

Larry,

Tim shot very well on all of the venues but that was an outstanding job on the flurry with one gun.

re. the offer to be your loader I'll have to decline as I don't want to be eating & sleeping in the servants quarters.