doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com George Newnham, 29 Commercial Road, London

Lloyd,
Wasn’t saying nix. I was saying think about it, hard. I hope it works out well, only because the alternative is really not well.

Merry Christmas.

Best,
Ted

as a general rule of thumb, it has been stated herein that any shotgun that is xxx number of years old...and shows some evidence (honest wear - consistent with it's age) of having been used....and has sparkling clean and bright bores - should be assumed to have been honed at some point in it's life.

i have adopted this concept into my thinking about the fine old guns we enjoy - i think of it somewhat like "guilty, until proven innocent". i assume that a 90 - 100 - 110 - 120 - 130 year old gun that has clean and clear bores, has been honed to achieve that state....and, i will continue to assume that until a bore gauge tells me that it ain't so.

when i see something that appeals to me, at a price that is also attractive, i will always ask the seller if they can supply dimensions of the chambers/bores/chokes - you might as well be asking for their bank routing and account numbers. i estimate that perhaps 1 gun nut in 100 has the slightest interest in these old guns that consume so much of our time/interest/money...and if you had 100 of those people, maybe 1 of them would have basic knowledge about these dimensions - and why they are important....and, if you had 100 of them, there might be 1 who actually has the most basic tools to accurately measure such things. hell, i doubt there's 1 american "gunsmith" in 100 who knows what we're discussing...and not 1 in 1000 who can measure a barrel.

so, we continue to work in the dark; i have just taken delivery of a 1929 jan visser ble (started a thread re: last week)...it's a very handsome gun, bought from a fairly knowledgeable guy who owes a brick-and-mortar gunshop in south louisiana. i made the usual request of him, and he replied that the bores showed no sign of having been altered. my bore gauge tells me the chambers were lengthened to 2.75", and the bores proofed at 18.3mm, have been honed to .730". the gun had a 3 day inspection, but i will keep it - it's too nice a gun, bought at a favorable price....and i have no doubt that it will handle the usual 1oz, 1150fps, handloads that i shoot.

life is a crap shoot, and we all have to calculate the odds for ourselves.

again best wishes for christmas & new years,
tom

No worries Ted. Merry Christmas one and all!

Lloyd

Terry Wieland, from his March 24, 2023 article in Grey's Sporting Journal titled "Damascus":

"Someone came up with the idea of persuading the shooting public that their old guns were not safe with modern, high pressure ammunition, and Damascus (or twist) barrels were the chosen fall guy. As the ammunition companies embarked on campaigns warning against the use of their ammunition in old guns, the gun companies ramped up their sales pitches for new steel alloy barrels. All of this was aided and abetted by magazines that were suffering in the Depression and needed the advertising. It became an article of faith, and pretty soon grandfathers and fathers were advising their offspring against Damascus, and we all know that Grandad knew about these things and was never wrong.

My late dear friend and colleague, Michael McIntosh, was told this by his father and never let go of the belief, railing against Damascus in print until (almost) the day he died. Even when he got to know many of the English gunmakers, premier barrel makers, and English proof house personnel, and was presented with irrefutable proof of the value of Damascus, he could never shake off the dread. Even his pal, English gunmaker David Trevallion, could not convince him. The best Michael could manage was to stop shrieking in panic in the pages of Shooting Sportsman, and maintain a sulky silence."

Another reason for the prejudice against Damascus seems to have been the introduction towards the end of the 19th century of dense nitro powders, loaded by weight rather than bulk powders which were loaded by volume.

Those who did not bother to read the instructions and used their existing powder measures blew up their guns both steel and Damascus.

As a high proportion of the guns then around were Damascus those barrels were tarred with some of the blame.

In the FWIW column here, I did talk to Kirby about my mild concerns for this gun and he was his usual helpful-self. I have his permission to run a few proof loads down the more honed-out left tube to see how it responds. My plans for it's use would be light 7/8 and 1-ounce loads anyway, so I was thinking an ounce and an eighth would be sufficient? Perhaps a standard clays target load? It is tempting to put it through it's paces with a really stout load (I have a few White Rhino Finocchi pheasant loads laying around that really belt you, and even some 2 1/2-inch high-bird British Gamebore shells that I remember being pretty harsh in a 6 1/2 lb John Blanch I had a few years ago). Decisions, decisions...at what price is peace of mind?

Lloyd: I'm sorry if I missed it, but I reviewed the entire thread and don't see the wall thickness numbers from end-of-chamber out to 9", which IMHO are critical
Today's powders, applicable for standard and light loads have, in general, a rapid rise and fall in pressure.
This is from the Alliant site, for 1 1/8 oz. 3 Dr. Eq., and pressures at 9" are less than 2000 psi



We fortunately now have a good collection of what are felt to be original wall thickness numbers, which could at least establish that your barrel numbers are similar. That, to me, would be reassuring.

Get well brother.

Dr. Drew:

As I understand it now, the right tube is as it was going through London Proof in 2017 and is stamped 18.5 mm on the flats (which translates to .728). The left tube, while also marked 18.5 mm, is in actuality now measuring .735. This gun was listed and sold as having 23k on the right tube and 20k on the left. At about 20-inches from the breech on the left tube, both Mark and I found a couple of thin spots of ~18k (on the left wall and near the top rib, [somebody has been chasing a pit]).

Now, two different tools were used to measure these tubes, Kirby's is lateral, the one at MW Reynolds is vertical and a copy of the one used at Holts (made & marketed by Tony Galazan here in the USofA) so there is clearly room for interpretation. Kirby has kindly offered to let me return the gun but is willing to allow me to proof-test it (in my own-way) here first. From looking at your pressure curve above (thankyou so-much for that!), I'm even more comfortable with it now.

Instead of measuring (& recording) the whole length of a barrel, I was trained to measure gun barrels by looking for the "thinnest-point" (which is what is recorded for most guns being sold these days). In almost every case, a gun being measured will usually be significantly thicker throughout the rest of the length of the tubes. If there is going to be a thinner spot, it seems to usually be in the 12 to 24 inch range on a set of 28 to 30-inch barrels, as it was here. I don't remember exactly, but these barrels were somewhere in the 40k range near to the breech and then thinning down in the 18-24 inch section. Since those "thin" spots very localized, at 9-inches from the breech I'd suspect that the tubes were still well-into the 25 to 30-thousandths range. The muzzles were also in the 20-25k range with the left tube being closer to 21k (& is probably the reason why it has so-little choke left).

Your pressure curve has also helped me decide the shells that I'm going to use for my little experiment. I really don't see much need to abuse an older gun any more than necessary, so 1 1/8 ounce target loads are going to be the ticket for me now, and I really don't expect any problems. A couple out of each tube should be sufficient.

The real challenge I'm facing these days is navigating on crutches in snow and ice(!).

Numbers are good Lloyd

William Thomson, 1st Baron (Lord) Kelvin
From lecture to the Institution of Civil Engineers, London (3 May 1883), 'Electrical Units of Measurement', Popular Lectures and Addresses (1889), Vol. 1, 80-81.
“When you can measure what you are speaking about, and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts advanced to the stage of science.”

Dr. Drew:

Since I am a "hard science" guy as well, I'll have to completely agree with you. But... in this particular case, my goal wasn't to advance "the stage of science", it was to advance my level of comfort with using this gun. After all the "data interpretation" from that mess on the barrel flats, to measuring it for myself, and then to finally...shooting a few 1 1/8-ounce shells through it, I'll have satisfied that need.

In the world I've lived & worked in, that's called "due diligence".