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Is my gun safe? What load was my gun designed to shoot?

207K views 75 replies 15 participants last post by  Drew Hause 
#1 · (Edited)
No one on the internet can tell you if YOUR gun is safe, with any load.

A adequate hands-on evaluation requires that the examiner has the interest, equipment (bore scope, wall thickness gauge, and the correct screwdrivers!), and expertise to properly do so. If your gunsmith is unable to tell you the wall thickness of your barrels from breech to muzzle, you need another opinion.

ANY vintage shotgun, regardless of barrel material, should be evaluated as follows:

1. Visually inspect for dents, bulge, wall integrity

2. Inspect bore for pits. Done right this would require a direct or fiberoptic digital bore scope. If not properly examined, you can not know the condition of the bore



3. Inspect and 'ring' barrels for evidence of rib separation (which might suggest a bulge)

4. Measure bore for evidence of previous honing. (I am of the opinion that any vintage gun with 'mirror' bores and no 'frosting' has been at least polished.)

5. Measure chamber length for evidence of lengthening, and measure wall thickness (WT) at the end of the chambers (recommended .105") and the end of the forcing cones (recommended .100")

6. Measure wall thickness from breech to muzzle, recording wall thickness (WT) 9" from the breech (.045"), 9" from the muzzle (.025"), and minimum wall thickness (MWT) in the distal 1/3 of barrel (no less than .020")

7. Remove the forend and assess lock-up

8. Attempt to pull triggers with safety engaged

9. Disassemble and check and clean the action, which likely has 100 years of congealed oil, grease, and field debris

Based on these findings, he who plans on shooting the gun will have additional evidence on which to base his decision regarding both using the gun and choice of shells. In no way does this evaluation guarantee the gun is 'safe to shoot'.

Additional information:
https://lcsca.clubexpress.com/content.a ... b_id=43784

https://docs.google.com/document/d/1ZIo ... c-kGA/edit

Turn-of-the-century Shotshells, Powder, and Ballistics
c. 1900
: The "standard" 12g field and inanimate target load was 1 1/4 oz. shot with 3 1/4 Dram Equivalent (1220 fps) of Bulk Smokeless with a modern transducer pressure of 8000 - 9500 psi.
Just before WWI: The "standard" 12g field and inanimate target load was 1 1/8 oz. shot with 3 Dr. Eq. (1200 fps) Dense Smokeless with a transducer pressure of 8,500 - 10,000 psi.
https://docs.google.com/document/d/1F2s ... FU/preview

Sherman Bell's destructive testing of a Parker GH with Dam 3 and a Parker VH with Vulcan Fluid Steel was published in The Double Gun Journal Vol. 10, Issue 4, Winter, 1999, "Finding Out For Myself" Part II and Vol. 16, Issue 2, Summer 2005, "Finding Out For Myself" Part IX.
Both guns were subjected to sequentially higher pressure loads at about 2,000 pounds/square inch (psi) increments. The GH testing started at 11,900 psi and one chamber ruptured at 29,620 psi. The VH started with a Proof Load of 18,560 psi. Both chambers bulged at 29,620 psi and ruptured at 31,620 psi.
That testing in no way establishes that YOUR unobstructed barrels would tolerate a pressure of 30,000 psi

We only have 10 fingers and 2 eyes



Mark Twain
"It is better to be careful 100 times than to get killed once."

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#2 ·
Please consider.
You sell a vintage Damascus or Twist barrel gun to a friend and advise that it should only be shot with a "low pressure" load. He takes it out back and shoots an AA Xtra-Lite Trap shell with a pressure of 8,000 psi. The barrel bursts and a piece of shrapnel enters the skull of his son.
At the civil suit, an expert witness has just testified that you exhibited "Gross negligence" (an intentional failure to perform a manifest duty in reckless disregard of the consequences, as affecting the life or property of another) by selling the gun as if it would be safe, since every shell box carries, and every powder maker states, a warning against the use of Damascus and Twist barrels.
You will be asked to prove/explain:
1. You examined the entire bore with a fiberoptic or direct bore scope, and have the expertise to identify and estimate the depth of any pits.
2. You measured the wall thickness, top, side and bottom, recording the minimum wall thickness every 1", and the wall thickness at the bottom of the deepest pits.
3. You measured and recorded the bore and external dimensions of both barrels prior to your "backyard proof test", and then repeated and recorded those dimensions.
4. Why you had confidence in your personal proof test and felt it was not necessary to send the barrels to a professional testing laboratory like H.P. White for proof testing.
5. Knowing the barrels were "Time Bomb" Twist or Damascus, why you did not send the barrels for Radiography, Magnetic Particle Inspection, or some other NDT.
And a bunch of other questions.

A.J. Aubrey steel barrel Model 18

 
#13 ·
Scary stuff.

I wouldn't fire one of those old guns even with black powder loads unless it was strapped to a table and I pulled the trigger with a 50ft string.

My dad bought an old 12 gauge single shot for $25 from someone but didn't notice a crack in the receiver by the hinge. When I pointed it out, he asked what I thought..... I said I'd give him $50 to throw it away.
 
#14 ·
The 'old gun' in the previous post is a Fausti. Here is an 'old' Miroku. Both shooters were using handloads.



The VAST majority of gun disasters are from operator error (in reloading or while shooting), or an irresponsible failure to adequately evaluate the integrity of the gun.

The point is that quality (which would likely exclude a single shot purchased from Sears for $3.85) vintage guns can be used, with shells with ballistics that reproduced those for which the gun were originally designed, with relative confidence after a careful evaluation as outlined in the first post, performed by someone with the interest, equipment, and expertise to do so.
 
#16 ·
mcookoc: What will be your explanation when a piece of shrapnel from your gun pierces the skull of your friend leaving him paralyzed, mute, and bedridden the rest of his not-much-of-a life? And what is your plan to pay for the lost wages, pain & suffering, and life-time care? Or do you only hunt and target shoot alone?
 
#17 ·
Hmmm,

That's irresponsible. Granted, I've field tested questionable guns, but it involved sandbagging them down on a rest, 50ft of twine and a barricade of some type to hide behind. Hardly laboratory quality, but safe.

BTW, none ever kaboomed.

When we shoot, there is always risk, even brand new. But why exponentially increase that risk?

Might want to get fitted for an eye patch mcookoc.
 
#19 ·
Drew Hause a gunsmith? Good advice there. Don't get an answer on the internet that might tempt you to fire it without having it checked out. Those photo's of blown up gun's point that out pretty clear I think. I see this kind of question quite a bit, is this gun or that safe? If your not sure, until you are certain, it's unsafe. Let's say you could replace that gun for $5000, pretty good price. What would it cost to replace a hand or maybe an eye?
 
#21 ·
Sept. 10, 1904 Sporting Life "Burst Gun Barrels"
http://library.la84.org/SportsLibrary/S ... 326021.pdf
The number of burst gun-barrels which, comes to the attention of the shooting public is remarkably small, considering the thousands of guns in use throughout the country. The main reason for the comparatively small number of guns burst is the great use of factory-loaded shells, or the hand-loaded of reliable dealers. The day of loading one's own shells is pretty well passed, therefore, the over-loaded or double-charged cartridge is very seldom found. Very often a burst barrel is blamed on the gunmaker or the shell-maker, but more often on the manufacturer of the powder. Cases are known where a party blowing out a gun-barrel, using an extra heavy charge of dense powder, blamed it on a bulk powder. A suit for damages was quickly withdrawn after an examination of the gun had been made.

A 3 Dr. Eq. (Dram Equivalent) load of "E.C." No. 1 or "Schultze" was 42 grains by weight. 3 Dr. Eq. of Dense Smokeless Ballistite was 24 grains; Infallible 21 grains. The pressure of a 3 Dram (82 grains by volume) load of Black Powder propelling 1 1/8 oz. of shot at 1200 fps is about 5000 psi. The pressure of 1 1/8 oz. 3 Dr. Eq. of BULK Smokeless was 6500 - 7500 psi; 3 Dr. Eq. of DENSE Smokeless was 9000 - 10,000 psi.
Substituting a Dense Smokeless powder for Black or Bulk Smokeless powder would double the charge. It has been estimated that 50 grains of Infallible (later Unique) could reach 30,000 psi. Combine this error with a 3" shell in a 2 5/8" or 2 1/2" chamber, and a barrel rupture might occur in any barrel, fluid steel or Pattern Welded.

Sears, Roebuck & Co. Catalogue No. 116 1907 courtesy of Gary Rennles
"When a gun barrel bursts at the breech or chamber it is caused by an overload of nitro powder, and when it bursts forward of the chamber it is caused by some obstruction..."
"Nitro powder should only be used by people familiar with it; and dense nitro powder should be weighed by an apothecary's scale and not measured."



Lots of infro here
https://docs.google.com/document/d/1F2s ... FU/preview
 
#22 ·
Drew:

I suspect you may be misleading some readers on the inherent safety of vintage (Circa 1900 or before) shotguns while minimizing the risks of handloading shotshells.

Accidental handloads with double, or even triple, charges of powder are known to destroy shotguns barrels. Even overloads of shot or incorrect primers may cause failures. I suspect that commercial shotshell manufacturers use various double checks of their loads while most handloaders ignore them.

I'm aware of no instances of catastrophic failures when firing safely loaded shells. To the contrary, misloaded shells can blow any gun, old or new. I have seen many pictures of failures that were attributed to misloads or plugs. If a cause was given for the failure none were attributed to weak barrels. The pictures you show include newer guns and guns blown by misloads. I didn't see one attributed to old weak barrels.

Sherman Bell performed the only comprehensive tests on the safety of vintage shotguns that I am aware of. He collected 30 old 12 Ga. wallhangers: Fluid Steel and Damascus barrels, American and Belgium made. They had numerous flaws such as corrosion, severely honed barrels, bulges and dents. Many were 'low quality' inexpensive Belgium guns or guns sold by Sears.

He subjected each gun to modern Proof Pressure firings of 18,500 PSI. All guns past these Proof tests with no bursts or bulging. He subjected two guns, one each with Steel and Damascus barrels, to increasing pressure until they burst. Both failed at about 30,000 PSI, almost 3x the maximum recommended 12 Ga pressure of 11,500 PSI.

A Metallurgist subjected the purposely blown guns to a detailed analysis. There were no indications of any of the corrosion extended internally to weaken either gun. There was no indication of any weakness in the welds of the corroded Damascus barrels.

Sherman had one guns' barrels machined out to 0.783" (technically 10 Ga bores) to a 0.046" wall thicknesses (about ½ the original) at 6" from the breech. It was still of marginal strength at Proof pressures: one barrel bulged on the first firing and then blew on the second while the other survived ten proof loads. BTW: over ½ Lbs. of metal had to be removed, way more than required to polish a bore.

The European minimum wall thickness standard can be seen at http://www.cip-bobp.org/sites/default/f ... 4-1_EN.pdf. It calls for a minimum thickness of 0.075" at 3.9" from the breech end of the barrel (about 1" in front of the cone) for low tensile strength steels. This appears to be consistent with the machined 0.046" wall being of marginal strength at Proof pressures.

One of the tested Twist/Damascus guns' barrels had previously been bored from the nominal .730" of a 12 Ga to .760" right and .764" left, leaving the barrels about 0.030" thinner than original and it still passed Proof pressures.

Sherman also performed tests to confirm the causes of failures of the shotguns (new or old). A double charge of a fast powder caused a violent failure at the breech end of a gun. Solid plugs caused failures near the plug.

His test guns had various loose and damaged parts including loose lockups. These flaws worsened when fired at Proof pressures while strapped in a cradle. There were no indications that these flaws presented safety problems; the barrels are the only pressure containing parts of a gun.

More details of Shermans' tests can be found at: viewtopic.php?f=13&t=259371&start=40 about 1/3 down the page.

I believe that inconsistencies in the manufacture of Nitro Powders, inaccurate loading information and the lack of proper loading equipment were the main causes of shotgun failure at the time, not weak guns.

Bob
 
#23 · (Edited)
Hunter Arms would agree Bob

Notice "All our guns are tested with heavy loads and cannot burst except by carelessness, obstruction in the barrel or improper home loaded shells with nitro or dense powder."



Thoughts regarding wall thickness

The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (C.I.P) minimum wall thickness recommendations for 'Standard Steel', defined as a tensile strength 101,500 - 123,000 psi:

For Standard Steel.............12g...............20g
Distance from the breech
Forward end of chamber - .079"..............075"
4" - .075"..................................................071"
8" - .043"..................................................041"
12" - .030"................................................028"
16" - .024"................................................022"
20" - .022"................................................020"

2.The average tensile strength of both Crolle Damascus and Twist is about 54,000, a bit less than Decarbonized or Siemens steel. There was however only a slight difference in the performance of pattern welded vs. late 1880s steel barrels in the Birmingham Proof House Trial
http://docs.google.com/a/damascusknowle ... edit?pli=1

3.Higher tensile strength fluid steel was developed rapidly after 1890.
Krupp Nickel Steel patented in 1890: 92,500 psi
Winchester Nickel Steel, introduced about 1896: 100,000 psi
Remington Ordnance Steel, introduced in 1897: 110,000 psi
ONE sample of Hunter Arms Co. Armor steel, introduced in 1898: 101,000 psi
1905 Krupp Chrome Nickel Steel D: 106,500 psi
Marlin "Special Smokeless Steel" introduced for the Model 1893 rifle in 1897 and Model 21 Grade C Pump in 1907: 100,000 psi

4.In 1918, Sears advertised the Fulton/Gladiator barrels as having a tensile strength of 85,000 - 95,000 psi.
The 'LLH' mark of Laurent Lochet-Habran is frequently found on L.C. Smith Royal, Armor, London, Crown and even Nitro Steel barrels from 1914 to 1948, Hunter Arms Fulton, Gladiator and Ranger for Sears, and also Fox, Ithaca, Lefever, and Baker guns.
This figure may therefore reflect the strength of the post-1900 Belgian 'rough forged tubes' used by most U.S. makers.

5. The industry standard for modern AISI 4140 Chrome Moly gun barrel steel is 95,000-100,000 psi.

Recommendation:

I would not shoot any barrel that is deeply pitted and has a wall thickness less than .020" in the distal 1/3 of the barrel because one cannot know the wall thickness at the bottom of those pits.

Every vintage shotgun, and shotgun barrel, should be evaluated before use by someone with the equipment and expertise to properly do so, and then shot only using ammunition with ballistics similar to that for which the gun was originally intended.


Evaluation and wall thickness recommendations are here
PLEASE NOTE: I have not found specification drawings or written statements by any turn-of-the-century U.S. or English doublegun maker regarding wall thickness; pattern welded or fluid steel. The recommendations are based upon numerous actual wall thickness measurement of presumed to be unaltered vintage doubles, by multiple U.S., English and Continental makers.
https://docs.google.com/a/damascusknowl ... c-kGA/edit

More information may also be found here
http://docs.google.com/a/damascusknowle ... edit?pli=1
 
#24 ·
Drew:

I had no intentions of questioning your suggested wall thicknesses. I was merely pointing out that Sherman Bell's failure tests on vintage thinned barrels were consistent with modern recommendations.

Sherman didn't report original walls thicknesses on the guns he tested, if I remember correctly, and I haven't been able to find any significant data on it. I assume the walls were often thicker than required by modern recommendations so that any barrels made of the lower tensile strength steels could pass Proofing pressures.

Since you have measured the wall thicknesses on many vintage shotguns (or have had them measured?) I am wondering if you could share the thickness results with us. Were there any indications that the barrels had been thinned internally or externally? Did you measure wall thicknesses on any blown barrels to confirm they were too thin?

Did you find any vintage barrels made of higher strength steels? I believe high strength steels had long been used in heavily loaded applications needing wear resistance like tool steels.

Alloy Steels were new at the time but they weren't the only method of gaining strength. Increasing Carbon content, quenching, annealing and work hardening were all well-known at the time. (Hardness tests are an easy way to estimate strength if anyone is curious; the higher the strength the harder the steel.) Names like Armour Steel and Ordnance Steel were only sales hype as far as I can determine.

You stress that "then shot only using ammunition with ballistics similar to that for which the gun was originally intended". The only information that I have been able to find suggests that the pressures, loadings and velocities of centerfire shotshells haven't changed significantly since they were invented in the mid 1800's.

Actually I don't see the need to know the ballistics of the typical ammunition of the time. Shermans' Proof Pressure testing showed that vintage shotguns, regardless of their make or 'quality', were capable of holding up to modern pressures and higher, even with flaws. Nothing else is important.

I must admit that I am a bit confused about your statement that "I would not shoot any barrel, pattern welded or fluid steel, that is deeply pitted and has a wall thickness less than .020" in the distal 1/3 of the barrel because one cannot know the wall thickness at the bottom of those pits." How would you know if it is deeply pitted if you can't measure the depth of the pits?
 
#26 ·
I don't see any pits. They are dents from some sort of physical damage. Possibly from one of the rotating bore hones with ball shaped abrasive heads gone wild. The raised edge on the one dent with enough light and shadow to see clearly is a dead giveaway. It was formed from metal that was displaced into the bore when the dent was made.

It should be relatively easy to estimate their depth by running a dental pick over them. The bottom of the dents is clearly shown. I doubt if they are much more than several thousandths deep; not enough to affect strength.

Pits have a very small diameter usually like pin points and can be fairly deep. The pictured dents look to be about 1/8" in diameter and are shallow.

At: http://www.doublegunshop.com/forums/ubb ... 668&page=5
You posted pictures of cut-off sections of vintage barrels; Damascus and Steel. You state there is no "orange lace" referring to the color and pattern that could be seen on the newly exposed surfaces of the Damascus if it were internally rusted.

A few pages later on: http://www.doublegunshop.com/forums/ubb ... 668&page=7
You stated:
"RESULTS ARE IN! And many thanks again to all who donated barrel segments, esp. Dennis Potter. I'm saving some of the good stuff for the article but:
1. The findings were remarkably consistent
After discarding the highest and lowest mean:
Twist - 53,300 psi
Crolle - 54,500 psi

2. Four 125 year old samples, Twist and Damascus Twist - 51,500 psi. I guess the mythical delaminating, rusting welds and voids don't really weaken Pattern Welded barrels over time smile

3. As Steve Culver predicted, the JABC Twist barrels were just as strong as the crolle samples."

Why are you claiming on this site that rusting welds, voids and pitting occur in Damascus types of steel while stating, along with pictures, on another site that they do not occur?

BTW: I hate to burst your bubble but the lack of internal rusting in Damascus was already reported by Xircon (sp?) who analyzed the barrels purposely blown up by Sherman Bell. Sherman reported that JABC barrels are as strong as any other Damascus barrels; they were probably all made in Belgium and all passed their Proofing standards.

I'm beginning to think that this Sticky thread should be unstuck and trashed before it misleads more people.
 
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