Franc,
I'm awaitinga written response to my questions and said I would not go public until I had received it, so, I won't. however, you might find the recent article I wrote for gun Trade News interesting:

When the Proof Houses change the rules, a bit of friendly consultation would be appreciated. The auction rooms have been alive with chatter about new tools, rejections and inconsistency. Diggory tries to unravel the stories behind the gun makers’ grumbles.

The Gunsmiths’ Tale
A well known dealer, with a busy repair shop recounted the sad story of his ‘sleevers'. He told me he has, for years, been submitting sleeved guns for re-proof after completing the necessary work. He has up-to-date chamber reamers from the USA and is sending his work to the proof house now, as he has done for over a decade, expecting the proof process to be carried out without mishap and have the guns returned with new proof marks. Last month a batch failed. He re-submitted them and they failed again. The first reason cited was shorter chambers than required, then they failed again because the diameter was deemed outside of required tolerances.

He has had identically prepared guns passed on a regular basis until now, using the same reamers and gauges. Suddenly, it is all change at the proof house and what was passable in June is a fail in September. Something has apparently changed. What?

Another long-established Birmingham gun-smith has totally given up on re-proof jobs due to recent failures and what he considers inconsistent regulations. “It is simply not worth the hassle anymore”, he said. Now he simply turns away any work that requires re-proof.

Another gun smith told me the “newly dogmatic application of CIP rules” was a hindrance to doing the job correctly, in his opinion. He had delivered a rifle with the rim cut precisely for the headspace he wanted and thought optimal for striking but had it rejected as ‘too shallow’, despite the head fitting exactly flush, as befitting best work.

A mass importer of guns reportedly submitted a batch of new Spanish guns to one of the UK proof houses. They failed view. He then submitted the same guns to the proof house in Spain (also a member of CIP) and they all passed without comment.

The Consultant’s Tale
A leading independent barrel maker told me he was aware of proof house modernisation, aimed at delivering the improvements in accuracy now available to the proof testers with modern equipment. The modern, German gauges are very precise and the CIP regulations are now being applied to the letter of the law. He believes this a good thing. It is better for the public and a “more correct” practice than previously applied. He agreed that it may not suit some ‘less expert’ gun makers than himself but was unapologetic as to the outcome, which he believes is in the long term interests of the trade. It should encourage everyone to raise their standards, in his view. The rationale is they all CIP stamped ammunition must fit all CIP proof tested guns of tent calibre or gauge. To this end, standard minimums have been set for chamber dimensions and standard maximums for case dimensions imposed on ammunition manufacturers.

He was of the opinion that when measuring older guns the proof houses would “allow a degree of leeway”, however, this does not appear to be codified in any official way at present and I’m curious as to how this might be provided for in the new protocols.

The Proof House Tale
Guns have been undergoing proof in London since 1637 and in Birmingham since 1813 so it may come as surprise to some that there could be any novelties in store during what is essentially the same process of view and proof that has been going on for hundreds of years in the same two places. A visit to the Birmingham Proof House allows one the remarkable experience of standing in the very same proof chamber that Greener illustrated with a woodcut of proof firing in his classic The Gun & its Development. It has changed not at all, save a hundred and fifty years of accumulated grime from powder burn and shot impact around the walls.

However, developments in the wider world of gun making and external standards of harmonisation imposed for elsewhere have impacted on the old practices. The CIP (Commission Internationale Permanente), an organisation based in Liege, is now, essentially, the governing body. Some gun makers have argued that we are now building guns to suit the CIP rather than building guns fit for purpose and having a proof test that confirms they are.

The Rules of Proof have not changed recently. According to the Birmingham Proof House website ‘The latest Rules of Proof, those of 1989, were approved by the Secretary of State to come into force on 1 November, 1989, but proof under earlier Rules of 1875, 1887, 1896, 1904, 1916, 1925, 1954 and 1986 remains valid provided that the barrel or action has not been materially weakened or altered so that it no longer conforms with the proof marks.’ There is nothing in this notice to suggest a change of practice in recent months. The trade could, therefore, be forgiven for assuming that what was good in 1989 is still good in 2014.

In the past there were two sets of chamber gauges at the Proof House - a Master Gauge, which was used as a definitive reference and a Working Gauge, which was used daily. If a chamber was marginal, the Master Gauge was brought out to give a definitive reading. It was used so infrequently that it retained its exact original dimensions, whereas the Working Gauge could be suspected of wear through repeated use.

When measuring chambers, the gauges would either be considered ‘go’ or ‘no go’ and stamped (or not) accordingly. Therefore, a chamber that would not accept the 2 1/2” gauge was considered ‘no go’ as being too small. If it accepted the 2 1/2” gauge but not the 2 3/4” gauge, it was passed for 2 1/2” proof. There were certain ‘grey areas’ that were always worked into the tolerances. Many chambers on older guns could be 2 1/2” or 2 5/8* or 2 7/8”, they would be considered as being within the 2 1/2” proof tolerances. CIP schematics allow no such grey areas - they specify dimensions for 65mm and 67mm chambers, as well as the 70mm that corresponds to the old 2 3/4” chamber.

The proof houses now have German-made Triebel gauges, which conform exactly to the CIP schematic drawings of what each gauge should measure in the chamber. It is more complex for rifles, with their plethora of calibre's and chambering permutations but for shotguns, the key measurements are the rim depth, chamber depth and chamber diameter. Using the new gauges, those tolerances are being applied rigorously.

I asked a staff member of the Birmingham Proof House if he knew of any memo to the trade or to any individual gun-makers who submit large quantities of guns for proof with regard to the new gauges and the exacting standards that were now being imposed. He said to his knowledge nothing had been sent. The Managing Director of a leading London gunmaker corroborated this; “I have never once been approached by the proof house’s since these new measures came into place.  We have had to adjust  to make sure our stuff is getting through, as have most people”.

My initial conversation with the London Proof House elicited a short response: “Procedures have not changed, we have just bought new gauges. They conform to CIP specifications, as should the old ones, though they may have been worn.” I brought up the subject of ‘grey’ areas with older guns and the response was blunt: “There are no grey areas as far as we are concerned”.

The Punter’s Tale
Mr Holder gave his Charles Osborne boxlock to a local gun shop to have it sleeved. It was his grandfather’s gun and he had sentimental attachments to it. Unfortunately, the thin old tubes had ruptured during use, thankfully without damaging anyone, and he wanted it rescued from the scrap heap. A sum was agreed, the insurance company paid out and the work to sleeve the gun commissioned.

A time scale was suggested and work commenced. The gun failed proof. Apparently the chambers were too short. Well, that is unfortunate, but these things happen. It was re-submitted. It failed again. This time the diameter was too small. He is now concerned. What is this gunsmith up to? Does he not know his job? Is he actually competent? He begins to get agitated and in turn puts pressure on the gunsmith. He wants answers, he wants his gun last month. It still has not passed proof. Who is going to sort out this mess? Why has it happened?

The gunsmith carried out the sleeving as he has always done successfully in the past, he is now concerned that his tooling may not be up to the task but has no clear feedback to give to Mr Holder to satisfy him that the issue is under control.

Conclusions
The new gauges and rules might be seen as a better and more precise system than the old one. Those making new barrels need to pay close attention to the tolerances that are acceptable and tool up accordingly with appropriately accurate reamers and gauges to ensure they conform to the new rules and practices. This sounds simple but it is costly and there appears to have been no warning or consultation with the trade at large to ensure a painless transfer from the old way to the new.

For old guns being submitted for re-proof, the issue gets more clouded. I would argue strongly that for a gun originally proof tested in 1875, the 1875 Rules of Proof should be retrospectively applied to it when re-proofing. In those days, the gunmakers and proof houses applied different tolerances. More variation can, therefore, be expected. If those rules were the ones under which the gun was made and deemed safe for use, unless the chamber has been altered, the same should apply now regarding chamber dimensions. To do otherwise would be the equivalent of an MOT tester failing a vintage Jaguar for not having anti-lock brakes.

This opinion appears to carry little weight, however, one auctioneer telling me “I know that the "new regime" is pretty tough in it's interpretation of the act, and there is little sympathy for old and collectable firearms.....  in fact no sympathy at all as far as I can see. The rules are black and white and of course this has led to issues with many older, antique and "obsolete calibre" items where it is argued that the act still applies regardless of legal status otherwise.”

The wider implication for the trade is the need to conform, so as to avoid repeated proof failures in future. A good start would be a close look at the published CIP chamber tolerance schematics. Lessons for the future? As with so much in business management, communication is the key issue. Had there been a pre-emptive consultation, a statement of intent or a set of clear guidelines disseminated by the proof masters to the trade at large, either through the GTA, the press, or directly, many of the problems recently facing gun makers and repair shops would have been averted. In the final analysis, it does seem apparent that any official (or unofficial) flexibility in the application of the proof laws has become a thing of the past.

The diagram below shows the points at which the chamber is measured and what minimum dimensions it must have to comply with CIP:

For example, a 12-bore 65mm chamber has to conform to the following minimum dimensions:

G = 22,55 + 0,10
R = 1,85 + 0,10
L = 65,10 + 2,00
I = 20,30 + 0,10
B = 18,20 + 0,70

Corresponding maximum dimensions for CIP approved cartridges ensure all commercial ammunition will fit in correctly sized CIP standard chambers.



Seeking clarification, I asked the proof masters for their official comments on the following questions:

1. When were the new Triebel gauges put into service?
2. What information or consultation went out to the Trade in anticipation of the changeover?
3. What percentage of increased fail rates has occurred since the new gauges were introduced? (Does not have to be precise).
4. Have the tolerances been changed with regard to measurements or is the only difference the fact that the new gauges are exact and the old ones were a little worn?
5. What rules are being applied to old guns, made when tolerances were more flexible under the then Rules of Proof and not materially altered in the chambers since then?
6. What advice would be useful for those submitting new barrels, sleeved guns or old guns for re-proof, in order to minimise the likelihood of rejection or failure?
7. What is the process now for guns with chamber lengths exceeding 65mm but less than 70mm - I’m thinking old guns with chambers that may be 2 5/8” or 2 7/8” etc.

The London Proof Master, Richard Mabbitt declined to answer the questions, saying he had been ‘misquoted on various occasions by the media’ in the past. As we go to press, I’m anticipating feedback from Birmingham, who are in my experience very open and professional in their dealings with the public and the trade.

I have a feeling I will return to this theme in the months to come. I would welcome some official input into the discussion by the Proof Masters, which would, doubtless, be both illuminating and appreciated by all those of us preparing and submitting guns for proof in 2015.