the Manson gauge

http://www.brownells.com/.aspx/pid=2...HICKNESS-GAUGE

there is a brace that is not shown in the picture that prevents twist

I have practised with it in several modes until I know I can get consistant measurements in different settings.

along with a Skeets bore gauge, a scale, a tape and a caliper (not in the pic) you have a compact set of tools that will give you some level of confidence when you consider a gun.

http://i248.photobucket.com/albums/g...-47-53_808.jpg

Jay, the gauge that Brownell sells for about $100 is the "Manson Gauge". Dave Manson worked with Clymer Reamers and went out on his own and built the gauge that bears his name. The "hanging from the ceiling" method of using the Manson gauge is now old tech and quite inconvenient compared to a method that I was taught by our friend Jon Hosford. Jon realizes that not everyone is a potential customer for his wonderful tool and generously shared this information with me. If there is interest, I will explain it on the forum again as I have in the past.

The Manson tool can be bought from Dave Manson directly if you choose. His website is mansonreamers.com. The shotgun reamers on the site are very nice items.

Bill,
Please do. I have one of the $100.00 gauges and am not convinced I am getting accurate measurements.
Thanks,
Ken

OK, here goes, as Jon explained to me and as I have been using ever since.
1. My gauge has a 5/16" hole in the "block", so I installed an eye bolt in the hole with the eye facing out.
2. I tied a generous loop of clothesline rope to the eye bolt with loops and knots to make holding on easier.
3. You need an assistant if measuring at a gun show or auction. The assistant needs no skill or strength.
4. The assistant will hold the barrels steady on a table with a cushion and the end to be measured over the edge. An assistant is to be preferred over a vise or weights, especially at a show or auction. No weight is heavy enough to hold the barrels steady.
5. The micrometer is zeroed with the rope holding one end horizontally and the ball supported at the other end by the fingers.
6. With the micrometer properly zeroed, the ball end is inserted into the barrel, run from the open end of the barrel to the extent of the rod and the results recorded. The rod must not contact the interior barrel wall for accurate results.
7. The assistant will rotate the barrels on the pad 90 degrees and the results recorded as in the previous instructions.
8. Another 90 degree rotation will complete the measurement of that end of that barrel. The fourth quadrant cannot be measured.
9. Do the same to the other barrel.
10. Reverse the direction of the barrels and do the same from the other end. This should result in 12 recorded minimum thickness measurements from one set of barrels.
11. In my opinion, this procedure, though a bit complicated, is much more convenient and accurate than the old method of hanging the gauge vertically.

John, if I were you I would do as your doing, describe the gun as completely and honestly as you have. If you believe the gun to be in original condition (no evidence or suspicion of honing or reaming) state that too. The gun is going to sell itself, it's unique and it's gorgeous. I am sure you are disappointed, but better to know now up front than have a buyer come back to you later with a potential issue to try to get some money back. I think you are in stronger position for knowing up front.

Sherman Bell's pressure test published in The Double Gun Journal Summer 2002, "Finding Out for Myself, Part VI, Smokeless vs Black", p.19 and summarized in Volume 17: Issue 4, Winter 2006, p. 39

1 1/4 oz. 3 3/4 dram GOEX FFFg Black Powder at 1240 fps and equivalent load Blue Dot
...........................1 inch.................. 6 inches...............12 inches
BP.......................5900 psi...............4100....................2100
Blue Dot...............6000....................4300.... ...............2300

1 1/2 oz. at 1236 fps Blue Dot (weight not stated)
...........................10,000................. 4,400...................2000

I'm a little surprised about the 10,000 figure, but 1 1/2 ounces is not a friendly load in a 12 gauge at that velocity anyhow.

Jay; Jay; Jay!!! -

Your absolutely excellent post looks like a court stenographer's transcription of the wonderful conversation that you, John Hosford and I had at the NE SxS in June! John's gauge paid for itself at about 15X MSRP in the first year I owned it. When dealers see you coming with it, they know whether to give you a little table space to set it up and measure or head for the Porta Potty across the parking lot in double time.

LOL: I know you guys are purists and love machines that measure things like barrel thickness. That's fine of course.

My method is simplier. I have several old shotguns...maybe half a dozen. I inspect dozens monthly. My method is to peer down the bore and then run my finger down the outside of the tubes. If the bore looks okay and I don't detect any bumps or ripples along the outside then I inspect the muzzles. If they don't look "spooky" thin, and the gun "talks to me", I'll make an offer.

What constitutes "spooky". Well, you've got me, but like pornorgraphy, I know it when I see it.

I copied this from a post I made over on the Doublegun BBS:

I sure have a lot of doubles with original chambers and forcing cones with wall thicknesses way below .100" at the end of the chamber.

Fox A grade 16ga, 26" barrels, 2-7/16" chamber, 0.085" and 0.086" minimum wall thickness at the end of the chambers, .734" and .734" diameter at the end of the chambers, 5/8" long forcing cones, #4 barrels, gun weighs 5lbs 9oz, serial 302XXX.

Parker VH O Frame 16ga, 28" steel barrels, serial 134XXX, 2-9/16" chamber, .082" and 0.085" minimum wall thickness at the end of the chambers, 0.730" and 0.732" end chamber diameters, 3lbs 2oz unstruck barrel weight, gun weighs 5lbs 14oz.

AYA #1 20 bore sidelock, factory 2-3/4" (70mm) chambers, 30" barrels, built and proofed in 2006, .092" and .091" minimum wall thickness at the end of the chambers. Skeets gauges unable to measure chamber diameter. Gun weighs 5lbs 13oz.


Fox XE 16ga, 30" barrels, serial 301xxx, .072" and .080" minimum wall at chamber ends, 2-7/16" chambers, .733" and .733" end chamber diameters, gun weighs 6lbs 3oz

Parker DHE 16ga, 32" steel barrels, serial 212XXX, 0.090" and 0.092" minimum wall thickness at chamber ends, 2-9/16" chambers, .735" and .736" diameter at chamber ends, barrel unstruck barrel weight 3lbs 11oz, gun weighs 7lbs 4oz.

Lefever H grade 16 gauge, 28" twist barrels, .090" and .092" minimum wall thickness at chamber ends, 2-5/8" chambers, .729" and .728" diameter at chamber ends. Gun weighs 6lbs 4oz

Ithaca Flues Grade 4E 16 gauge, 28" Krupp fluid steel barrels, 0.091" and 0.092" minimum wall thickness at the end of 2-5/8" chambers, daimeters of .728" and .730" at the end of the chambers, gun weighs 6lbs 6ounces.

Parker DH 12 bore, 28" Damascus barrels, 1 frame, .086" and .090" minimum wall thickness at end of the 2-5/8" chambers, gun weighs 6lbs 14oz. Serial #84XXX, My Skeets gauges are incapable of measuring the diameters at the end of the chamber.

Bissel Birmingham boxlock, 20 gauge, 25" steel barrels, made in the 1920s, .084" and .092" minimum wall thickness at the chamber ends, 2-1/2" chambers. My Skeets gauges are incapable of measuring the diameters at the end of the chamber. Weighs 5lbs 7oz.

Mike, looks like you have an interesting collection of 16's. Which is your favorite? Dave

This has been a great and informative thread. In that regard, what's the consensus on the safety shooting factor of this DH? I do note that the chamber/forcing cone minimum barrel wall thickness measurements are needed.

http://www.gunbroker.com/Auction/Vie...Item=304446791

To my eye those barrels look plenty thick. The safety of shooting those fine damascus barrels has been much discussed here. I suggest you find Sherman Bell's articles in Double Gun magazine. He has done extensive research and many tests shooting those damascus/twist tubes. He had a difficult time getting them to let go, even when shooting modern proof loads.

You can also buy lighter loads made specially for the older guns. Look up RST and Polywad shot shells.

Summery, you can find very safe ways to shoot and enjoy guns like these and if in good condition, they are safe when shot with proper loads.

David I couldn't choose one. The Parker VH 16 and the Fox A grade 16 are neck and neck for my favored Bob White gun. The stock is lower on the Parker and I shoot it a little better.

The Fox XE is a fine gun and maybe the prettiest gun I own. 30" barrels make it nice for dove.

The DHE 16 with the 32" barrels is a great dove gun. A few years ago I took it to Argentina.

I shoot the Flues very well, perhaps better than any other gun I own.

Besides the list above I also have a Parker VHE 16 O frame that weighs 5-3/4 pounds with 26" barrels that I really like. And a Birmy boxlock 16 (Gallyon) the weighs in at 5-9 with 28" barrels that was my first love in double guns.

So I guess the answer is that I don't know.


And thanks!

Mike

Jay's long response to this question is first class. Factual, logical and to the point. I for one copied it into Word so I can refer to it without having to search for it and show it to friends who might ask the question. Thanks Jay. Very well done.

Back to top. Persons interested might read Jay Shachter's post.

This information was part of a separate thread, but will add it here
http://parkerguns.org/forums/showthread.php?t=10889

Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (C.I.P) http://www.cip-bobp.org/

Shotgun recommended minimum wall thickness p.4

http://www.cip-bobp.org/sites/defaul...e/A-4-1_EN.pdf

For 10 & 12g Standard Steel................................20g Standard Steel

End of chamber - .079”............................................. ....... .075”

Just past the forcing cone/ 4” from breech - .075”................. .071”

8” - .043”............................................. ........................... .041”

12” - .030”............................................. ......................... .028”

16” - .024”............................................. ......................... .022”

20” - .022”............................................. ......................... .020”

FAQ http://parkerguns.org/pages/faq/BarrelThickness.htm

And that correlates to what service and proof loads?

There are three pressure measurement systems (lead crushers/LUP, copper crushers, and piezo), and two standard systems of measure units (USA/SAAMI and CIP/British/European) and two differing units (psi and tons and BAR in kg/cm sq) within each system, different proof laws by country, and differing proof laws by age.
Unfortunately, there is essential NO formula to convert BAR expressed as LUP (CIP) to PSI (SAAMI). LUP + 1000 does not reliably predict the actual piezoelectric transducer measured pressure.

That said, European (CIP) "standard" proof pressure of 850 kg per sq. cm. (BAR) = about 13,920 psi proof pressure = 10,730 psi service pressure (SAAMI)

So are you saying that the commission wall thickness recommended minimums correlate to the commission stated proof loads and service loads? So that if these are the commission recommendations, where do some of the figures that we see thrown out come from? Such as no less than .025 or .030, or pressures no more than 5000psi or 8000psi? I've often wondered where these figures come from and not seen a clear explanation, often its " what is used in England" but what I've seen before it what you published .

Bruce: In the words of Will Rogers "All I know is just what I read in the papers (and on the internet), and that's an alibi for my ignorance."

I'm a bit stunned regarding the .075" recommendation just past the forcing cones :shock:

My NON-EXPERT opinion: It's a lot easier to give pressure recommendations since that information is what shell makers give, when we all know, when using shells for which the gun was originally intended, IN UNALTERED AND INTACT barrels, the primary issue is recoil and the effect thereof on both lock up and the 100 year old wood.

Since the mid-1890s the guns were designed to be used with Nitro Powder

http://pic20.picturetrail.com:80/VOL.../406656956.jpg

Remington Model 1889 "For Nitro Powder"

http://pic20.picturetrail.com:80/VOL.../406313078.jpg

And we know the old boys were using some real boomers :whistle:

Jan. 2 1897
http://www.la84foundation.org/Sports.../SL2815017.pdf
Charles Grimm defeats Doc Carver in Chicago for the “Cast Iron Metal”
Grimm used a 12-bore L.C. Smith gun, 7 3/4 pounds, 3 3/4 drams Schultze, 1 1/4 ounce No. 7 shot, in U.M.C. Trap shell.
Carver used a 12-bore Cashmore gun, 8 pounds weight, 4 drams of Carver powder, 1 1/4 No. 7 shot, in U.M.C. Trap shell.

However, very few of us can know what sort of abuse our vintage guns have been subjected to over the last 100 years, the wood is now 100 years old and may well be oil soaked, so prudence might suggest using a Benelli SBE for 3" 1 3/4 oz Fiocchi Golden Pheasant loads like most of the low life philistines with whom I hunt S. Dakota & Kansas pheasants :rolleyes:

Additional commentary regarding the 1891 Birmingham Proof House Trial in Frederick Toms' Sporting Guns and Gunpowder, 1896

'Experiments On the Strength of Gunbarrels' starting on p.9
http://books.google.com/books?id=inQ...AJ&pg=PA16&lpg


"These experiments serve to show what a very large margin of strength there is in a good gun barrel, when ordinary charges are used. They also tend to prove that the brazing process (if properly carried out) does not injure the metal to any appreciable extent. It has frequently been alleged, by opponents of the proof test, that, although the barrels may pass through the proof without any apparent injury, yet the large charge strains the metal to such an extent that the barrels are likely to burst afterwards when used with ordinary charges. The fallacy of this argument appears obvious when the fact is taken into consideration that the barrels which gave way earliest under these tests had withstood the strains of nearly thirty successive trials, the first of which was rather more severe than the definitive proof charge, and the average of the whole was about four times as great as the regulation proof; while the steel barrels were tested forty times, with charges averaging nearly five times as much as the ordinary proof-charge.
Taking the cumulative grain test, as calculated in the Birmingham experiments, the strains undergone by each of the two steel barrels were rather over 110 times as great as that of the definitive proof test; and those of the Damascus were rather over 120 times the definitive proof in the case of the barrel that had undergone the brazing process, and nearly 130 times in the barrel that were not brazed. So that, although the steel barrels showed the greater amount of endurance, the strength of the Damascus was so much in excess of all ordinary requirements that no fear need be felt of their giving way when the work is properly done."

https://docs.google.com/document/d/1...EK8OtPYVA/edit

Regardless we still get people asking here how they can get black powder loads so they can shoot their 1895 Parker damascus and we still get forum participants telling others to keep pressure "low". Of course what they really mean is low recoil for weak stocks but some stocks aren't weak at all. And some tell others to stay under 6000 or 8000psi because that is what damascus guns were designed for , with no authority cited.

Like you I do not feel that these super duper heavy loads are needed, but my point is that these old Parkers are strong guns and built to take some stout loads, then and now.

So we should no longer advise folks to shoot their Damascus guns only with appropriate loads?

I contend that a 1925 6-1/2 pound 12 bore Birmingham boxlock was designed to shoot, day in and day out, 1-1/16 oz at about 1,150fps and sub 9,000psi. It was proofed at about 15,000 psi if memory serves. It was stamped by the proof house at 1-1/8oz.

My little Chrysler Crossfire is capable of putting out 215hp and maintaining a top speed of 150mph. But it was designed for , day in and day out, cruising at 80mph and quick but not constant full throttle acceleration.

In the period guns I am interested in the British service load was always less than the maximum load. So a 16 was stamped by the proof house "1oz" but its service load was 7/8oz. A 20 was stamped "7/8oz" but its service load was 3/4oz. The 12 was stamped 1-1/8oz but its service load was 1-1/16 oz. This information is in a table in one of Burrard's three volumes.

Even the lowly Damascus Crescent sold by Sears in 1900 was "Bored For Nitro Powder"

http://pic20.picturetrail.com:80/VOL.../405627118.jpg

re: appropriate loads for which the gun was designed in the inferior Smith guns :)
http://www.lcsmith.org/faq/loads.html

Bruce has posted an image of the Parker recommended loads several times

Tell them the appropriate loads and pressures that their gun was designed for .
Isn't that something you'd like to know if you were new to Parkers?

Dean, We could go back to the old panic about damasks barrels and advise all to sell all those guns as they are unsafe. We will buy and buy, in the by and by. David

I'll presume you're being facetious.

Yes, every owner of a Damascus barreled gun, Parker's in this discussion, should be informed of the loads their guns were proofed with, but I don't think we should ever presume to tell them to shoot anything but appropriate loads in their guns because WE have no idea of the condition of the stocks or the barrels of their guns. I would prefer they err on the side of caution rather than throw caution to the wind and shoot "off the shelf" ammo that will fit in their chambers.
I really see no point in discussing this issue further so I'll bow out.

may we also add that the proof was done in original condition and many if not most damascus and even early steel barrels have been "cleaned up"

so what they were proofed for and what they are now safe with are likely two different things. one of my letters states it went back to have barrel work including opening the chokes and back again years later to be "cleaned out", comparing the condition of the outside to the shiny insides when I found it I have no doubt it was done a third time.

all this left a minimum of 30 thousands in the front half. comfortable by most folks standards.

people new to damascus have concerns, they should be taken seriously, then educated

Dean, I do apologize for my facetious remark. No offense was meant. I was only trying to say the same thing you said: This post is exhausted. Sorry, David

Hey David - No apology is necessary.

I completely understood your comment and find no fault with it at all.

I hope I didn't come across as a grouch. If I did I apologize for that.

Gentlemen and others,

I am reviving this thread about Minimum Barrel Wall Thickness because that question was asked elsewhere. If you are wondering about minimum barrel wall thickness please read this entire thread for a quick but solid education on the subject!

Mark

We do have more information now that the tensile strength of both pattern welded and fluid steel has been reported. Short version is here
http://www.lcsmith.org/faq/thickness.html

Thanks Drew,

We need to incorporate that into facts page of this PGCA site, with your permission of course!

Respectfully,
Mark

Of course :)

I don't want to give everything away before the article, but this is relevant:

Winchester Nickel Steel from Bethlehem Steel Co. Jan. 1900
http://books.google.com/books?id=Yzh...J&pg=PA181&lpg
Tensile Strength 106,900 psi

Courtesy of Walt Snyder, A.P. Curtis, General Manager of the Ithaca Gun Co. requested composition analysis and tensile strength testing on a section “cut from a barrel made in Belgium” performed by E.J. Stormer, Racine, Wisconsin in 1919. Tensile strength was “about 70,000 psi”.

This should be a "Sticky" Please

What is the numerical correlation between barrel tensile strength and barrel rupture psi ? I thought the relevant measurement was psi at rupture as an indicator of ultimate strength

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