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

Dr. Drew: You are correct about the "not for ball" situation, so that begs the question...is this gun pre-1887? The serial number range would certainly have one think so (presuming that the records are representative here). Parabola may have solved it though, if the honing of these tubes (over several episodes!) has produced this minor constriction. I would also point out that "choke" is stamped on the left tube (but not the right). Not sure I've ever seen that before.

Lloyd,
Many old English guns have no choke in the right tube, and bunches of it in the left.

Just the way it was.

Best,
Ted

any of the reproofs, up until 1954, could have been the origin of the left tube receiving the "choke" stamp....at some point, any constriction of 8 thou (or more) earned a "choke" stamp - and as parabola points out that condition might have been met many decades after the gun was built.

on diggory's handy chart of english proof marks, it becomes apparent that it is possible to see a gun built - without chokes, that might possibly go through proofing with exactly the same markings from 1855 until 1887. in the 1875 - 1887 era, he shows the london markings as "12 or 12B 14M"....while the brummie markings show only the "12B 14M" (but, that might just be for lack of space in his format....why would a "B" be needed if there were no choke?).

my dougall lockfast appears to be very close to the 1875 dividing line (sn 3147 - with london proofs), and i have puzzled if there might be a way to definitively place it "before/after"....but it was built cyl/cyl - and the proofs offer no indication.

looks as if they could have shown a bit more foresight, in differentiating between the time periods....but, as i often say - none of us need glasses for hindsight.

best regards,

tom (and, i am reassured to know that i'm not the only fellow spending time here over the Christmas weekend - hope your's is happy & bright)

There is a lot of information to digest on those barrel flats, and much of it had been obscured by crowding (& presumably by previous barrel refinishing events) over the years. I don't know how many times a set of shotgun tubes can be sent for re-proof, but for me this one takes the cake. How many episodes are we talking about here? I'm counting at least 4 separate sets of proof marks, isn't that right? If you'd hone those tubes any more they'd transmit light(!), it's no wonder the gun weighs so little.

From my measurements yesterday, I'd have to guess that the left tube was reworked substantially after that 2017 London reproof, since 18.5 mm works out to about .728 (by my math) and the left tube now measures .735. So....that's 7 thou difference between the left and right tubes now. Would that explain the .010 constriction on the right while being .003 on the left?

That begs yet another question, at what point do these thin tubes become an issue? It certainly limits the use of the gun to only 7/8 & 1-ounce low-pressure loads (in my mind). For casual strolls down pretty Fall grouse trails it should still be fine, but I'll have to carefully restrict it's use by my son (& myself) to those ideal situations. Thank goodness we still have an 870 or two laying around.

I'm going to talk to Kirby about it, and ask him if I could send a few 1 1/8 ounce target loads down that left tube first (before surrendering my right to return it). I'd expect that it would digest them just fine, but...it'd be nice to know that.

Please do not get too disheartened Lloyd.

Whilst the British gun trade regards 20 thou minimum wall thickness as “minimum recommended wall thickness“ this is more with a view to having sufficient metal to deal with raising dents and knocking down bulges than as a concern about the possibility of bursting.

Quite a few very light guns, particularly 2” guns, seem to have left the factory with MWT in the high teens.

Remember that a bore enlargement of 7 thou, assuming concentricity, is only a reduction of 3.5 at each wall, and that MWT being close behind the muzzles will be at a point where the pressure curve for a shotgun cartridge has fallen to a small fraction of peak pressure.

As you have a minimum of 20 thou you should be fine with any 2 1/2” cartridges loaded to CIP pressures.

But remember the rule of 96, and out of respect to your shoulder and the stock don’t use more than 1 ounce in a 6 pound gun.

Season’s Greetings

Parabola

Parabola: Thank you.

I've tried to get worked-up about these honed tubes and I just can't. After re-reading Sherman Bell's stuff (from back in the early 2000s) I'm just not that concerned this gun will be a problem, and you're right about the 2-inch guns (I've seen that firsthand). The fact that they're fluid steel likely helps (by adding about 20k psi tensile strengh) over comperable Damascus, but even 17 and 18k wall thickness stuff has passed proof in England and gone on to years of use with no problems. If you have a barrel obstruction, then God help you(!), but otherwise....gun barrels just don't fail without massive (& usually obvious) structural flaws. I would be curious to know though, at what point is a tube just too darn thin? Where is that "no-go" point actually at? Where it dents too-easily?

And finally... I agree that the "Rule of 96'" is well-worth observing, if only for the preservation of any 100-plus year old wood a fine gun might have The "comfort component' is noteable as well.

Lloyd,

Not that I would use it as a recommendation but I recollect a thread on this forum where the owner of a German or Austrian over and under found he had an unsaleable gun when he discovered that the MTW was 7 thou although it had never had any barrel work since new.

Whilst sympathetic to his plight, I was struck by the fact that it seemed to have survived half a century of regular use without exhibiting any problems.

Lloyd,
Hmm. I don’t know, what I don’t know, but, a pattern welded barrel provides what the engineers refer to as stress risers, and lower tensile strength to boot. If everything goes perfect at the place that loads your ammunition, and there isn’t a thin coat of oil in the bores of your gun left from last season, or, some other simple mishap, maybe, just maybe, .020 is, as our English brothern’ say, “adequate”.

Maybe. The engineers spend a lot of time on the margins, thinking about how to make something just a little bit stronger than it has to be.

This is going to be your kids gun, right?

Let me put this another way. The people who built my Halifax in the very early 1920s used a top flite grade of Siemens Martin steel, and left the walls at no less than .050 the entire length. Those tubes were going to have to contend with French proof that was hovering around 18,000psi, but, the French guys could have made them thinner. They could have.

They didn’t.

Just something to think about.

Best,
Ted

I have a tired canvas, leather edged, makers case for 30" bbls with 3rd fastner. The label is

George Newnham
Gun & Rifle
Manufacturer
29 Commercial Road
Landport
Portsmouth.

The case might be too far gone. The label is fairly decent.

Text me at 7o4 577-318o. I'll snap photos.

Joe in Charlotte

Ted:

I've made my living for that last 30 years or so as either a government contractor (or as a government scientist) and the job has always been basically the same...managing risk. I evaluate the facts, the science, the politics (and my "gut") and then make my call. I've lived with that process long enough now to be pretty comfortable with it. You choose to ride a fast motorcycle in Minneapolis traffic, my 20-year old son drives a '60 Dodge Dart (w/shitty drum brakes) and neither of which would I be fully comfortable with driving myself. We are going to have to disagree on this one.

This gun is serving a purpose for me by appearing under a Christmas Tree this year. Knowing how my son tends to see these things, he'll appreciate it for a week or so and then go back to his life as a college student (where girls and cars are much more important, as they should be). He'll possibly use it next Fall up at his grandfathers place, and by then I'll have throughly vetted it in my own fashion (w/a few proof loads). I'll mike the tubes, burn a few and mike them again. If I see any changes then back to Kirby it goes.