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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



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#52 ·
Drew Hause said:
Stepmac: just to clarify, the H & D Folsom Arms Co. Catalogue No. 35 (1930-31) listing for the New "Empire" (Crescent No. 9) states the barrels are "Fine Decarbonized 'High Pressure' Steel - Proof Testing with loads considerably heavier than standard loaded shells".
The Club Hammerless was in the 1900 Sears catalog (Crescent Model 1896 side lever) "Bored For Nitro Powder" with "blued decarbonized steel barrel". In 1902 it was listed with "rolled steel blued barrel...the best grade of Wilson's steel".
The 1902 Sears catalog also listed the 16 gauge "Automatic Ejector Single Gun", a Crescent No. 8 "Bored For Nitro Powder" with "Decarbonized Armory Steel Barrel".

So I believe Crescent's "Armory Steel" was decarbonized steel rather than fluid steel, but am still looking for a chunk of Crescent barrel for composition analysis.
Not bad stuff, and with a bit more tensile strength (esp. if "rolled") than pattern welded barrels:
Bessemer or Decarbonized Gun Barrel Steel: 55,000 - 70,000 psi with an average 63,000 psi.
It is likely some of the barrels were similar to AISI 1018 Low Carbon (Mild) Barrel Steel: 64,000 psi.
Winchester Standard Ordnance (Bessemer Cold) "Rolled" Steel tensile strength as 69,400 psi.
Marlin Model 1898 Slide Action Shotgun "Special Rolled Steel": 66,000 psi
It is assumed the "Remington Steel" used on the K Grade (Model 1900) Hammerless and (1894) Hammerless Grade "F.E." Trap Gun (introduced in 1906) is similar.
"Parker Steel" used on Grade 1 PH & NH after 1917 is Decarbonized Steel.

Actual tensile strength testing of c. 1900 U.S. maker's fluid steel barrels is similar to modern 4140 gun barrel chrome moly steel at about 100,000 psi.

Measured black powder pressure are significantly lower than smokeless:
3 dram / 82 grains FFFg 1 1/8 oz. (1200 fps) is about 5000 psi.
3 3/4 dram GOEX FFFg with 1 1/4 oz. (1240 fps) is about 6000 psi.
4 drams of FFFg / 108 gr. with 1 1/8 oz. (1420 fps) is about 7000 psi.
Thank you for your post! To find Bell's numbers I have to dig thru about a three foot tall stack of old "Double Gun" magazines. I'm sure your numbers are correct. While serial number/dates are hard to find, I think my Dad's 20 gauge Crescent was made in 1901 or 02. His dad shot a 12 gauge Remington Model 11. I know that dad loaded it with what we used to call "high base 5's" to shoot at ducks alongside his dad. These being the most powerful loads of the day. No such thing as a 20 gauge magnum in those days.

I have never shot anything other that light skeet loads in any of my 1900 era shotguns. The Lefever "I" grade 12 gauge is extremely light, even with the 30" tubes. I shoot it at Clays and enjoy it.
 
#54 ·
Unlike Blackpowder, which essentially has a single composition, there's a wide range of Smokeless powders. It's likely, but not certain, that commercially loaded shells use fast burning powders to reduce the weight of powder needed and therefore their cost. This probably pushes their pressures to near the max recommended pressure of 11,500 psi for a 12 gauge even for light target loads.

It's not hard to find loads in the reloading manuals that have pressures/velocities similar to BP loads. This is an example of a lower pressure load from Hodgdons' Loading Manual (http://www.hodgdonreloading.com/data/shotgun):

For 1 Oz. of shot, using SR7625 Powder and a 12 GA, 2 3/4" Shell:
21.5 grs > 4,700 PSI and 1,100 FPS
22.5 grs > 5,200 PSI and 1,150 FPS
24.0 grs > 5,900 PSI and 1,200 FPS
25.5 grs > 6,600 PSI and 1,250 FPS

Sherman Bell pressure compared a 1 1/4 ounce loads of 3 3/4 drams GOEX FFFg vs. Blue Dot, both at 1,240 fps, which gave nearly identical results:

@ 1" from breech - Blackpowder = 5,900 psi, Blue Dot = 6,000 psi
@ 6" from breech - Blackpowder = 4,100 psi, Blue Dot = 4,300 psi
@ 12" from breech - Blackpowder = 2,100 psi, Blue Dot = 2,300 psi

Firms like RST, Polywad and New Era can supply factory loaded low pressure shells. See viewtopic.php?f=13&t=259371&start=40 about 2/3 - 3/4 down the page for more info.

An advantage of BP is that you probably couldn't fit enough of it into a shell to overpressure any shotgun.
 
#55 ·
I just returned from the skeet range. I shot my new old Browning Auto 5 16 gauge shotgun. Gun made in 1930 or 31 probably and not a "Sweet 16". Gun carries #3 engraving, very pretty. Shooting RST 16 2.5" shells advertised at 1200 FPS. I set the rings up for light loads and the gun functioned well. The RST people told me that at first their shells were not cycling Auto 5s so they loaded a faster powder. I thought I could hear or maybe feel the forearm being smacked. I am going to change the rings to heavy loads to see if it will cycle. I shoot Auto 5's wet and had coated the magazine tube with Rem Oil to help it cycle.

I had never shot this gun before and did not do well. I was shooting high. The gun feels good. If I carried a very fine bead I did better. I don't look a the bead when tracking the bird and only use it to mount the gun. Next time I'll do better. I only shot one round.

I have never reloaded shotshells, but will probably start to reload these short 16's.
 
#56 ·
A thread here stimulated a very interesting discussion on DoubleGun
http://www.doublegunshop.com/forums/ubb ... 176&page=1

1897 - 1903 only [did] the Belgians provided specific load instructions. It took some help interpreting the marks, but it's been a valuable learning opportunity

Pre-1924 Manufacture Liegeoise d' Armes a Feu 16g
Bore 17.0mm = .669"
Right choke 16.9mm = .665" = Improved Cylinder; Left choke 16.4mm = .646" = Improved Modified
Proved with E.C. No. 3 - "New E.C. (Improved) No.3" was Bulk Smokeless powder and was introduced in the U.S. in 1904; 11 grains = 1 dram equivalent.
Load markings: 1.81 grams "poudre" = 28 grains; E.C. No. 3, Walsrode Gray or Mullerite No. 2 = 2 1/2 Dram Equivalent.
24.5 grams "plombs" (lead) shot is 7/8 oz.



Here's a 12g intended for the U.S. market with load data in American :) A 33 grain bulk powder = 3 Dram, with 1 1/8 oz. shot



Thanks to the OP for getting this started!
 
#57 · (Edited)
More turn-of-the-century pressure data

G.T. Teasdale-Buckell, Experts on Guns and Shooting, 1900
Experts on Guns and Shooting
1 1/8 oz. load comparisons. Pressure converted used Burrard’s formula
42 gr. = 3 Dram Bulk Nitro – 1” chamber pressure 7,985 psi / MV 1208 fps
45 1/2 gr. = 3 1/4 Dram – 9,730 psi / MV 1,274 fps
49 gr. = 3 1/2 Dram – 11,780 psi / 1,328 fps

Winchester Factory Memorandum dated February 6, 1900
12g 2 5/8" Leader with 1 oz. shot
40 gr. DuPont Bulk = 3 1/4 Dr. Eq. = 2.7 tons X 2240 = 6,050 psi
42 gr. Laflin & Rand Bulk = 3 1/2 Dr. Eq. = 3.3 tons X 2240 = 7,400 psi
12g 2 5/8" Leader with 1 1/8 oz. shot
40 gr. DuPont Bulk = 3 1/4 Dr. Eq. = 3.9 tons X 2240 = 8736 psi
ALL Plus 10-14%

Forest & Stream, September 24, 1910 from The Field
Forest and Stream
42 gr. (3 Dr. Eq.) “Schultze” with 1 1/8 oz. shot = 9,598 psi (by Burrard’s conversion so adding 10-14% is not needed)
33 gr. (3 Dr. Eq.) “E.C.” Improved No. 3 with 1 1/16 oz. = 8,758 psi
33 gr. Smokeless Diamond with 1 1/16 oz. = 7,952 psi
33 gr. Red Star (New Explosives Co., Stowmarket) with 1 1/16 oz. = 8,322 psi
 
#58 ·
"1897 - 1903 only the Belgians provided specific load instructions. It took some help interpreting the marks, but it's been a valuable learning opportunity"
The British used load data for marking optionally Nitros Proofed shotguns beginning with their 1887 Proof Rules. Only Schultze and E.C. Nitros were available at the time. You can see a reference to the markings at: http://www.shotguns.se/html/uk.html.

A typical marking was 'Max'm SCH 45 Grs. Shot 1 ¼ oz'. SCH stood for Schultze, the first commercial Nitro Powder. It actually had some Potassium Nitrate Oxidizer in it making it a Semi Smokeless powder. E.C. Powder was also used.

These marking are very rare. "Sporting Guns and Gunpowders: Comprising a Selection from ..., Volumes 1-2, By Frederick Toms" Reported that in 1891 of the 40,827 choked shotguns proofed in Birmingham only 28 were proofed with the optional Nitro Proof.

This can be confusing: if you are lucky enough to find a gun with markings something like "Max'm SCH 45 Grs. Shot 1 ¼ oz" it is actually Nitro Proofed w/o the 1904 and later 'NP' marking.

The 1896 Rules listed several brands of Nitro powders along with their Proof loadings and typical service loadings. They would have an unspecified abbreviation of the powders name.

An possibly rarer subset to the markings occurred under the 1896 Rules when the gun sender requested a Nitro Proofing w/o specifying a particular powder. In this case the gun is Proofed with a fine grained Blackpowder which, according to pressure tests in the book, actually produces a higher pressure than typical Nitro Proof loadings. In this case the gun is marked with "Nitro Proof oz. maximum" with the oz. indicating the service weight of shot to be used.

Seems odd that the first 'Nitro Proof' marked guns were actually proofed with BP.

The 1896 British Proof Rules can be seen on page 1 of the referenced book, see: https://books.google.com/books?id=inQCA ... es&f=false . It has some information on the 1887 Proof Rules but I can't find a complete copy of the rules.

A summary of the 1896 Rules along with some of the Proof Pressures can be seen starting at the bottom of the page and on the next page at: viewtopic.php?f=13&t=259371&start=140
 
#59 · (Edited)
Summary of c. 1900 pressures, extrapolated to modern piezo transducer numbers

The reported pressures are converted to modern piezo transducer numbers using Burrard's formula if originally expressed as Tons/sq. inch by LUP (Lead [Crusher] Units Pressure), or by adding 10-14% if expressed as PSI by LUP

c. 1900: The "standard" U.S. 12g Field and Inanimate Target load was 1 1/4 oz. shot with 3 1/4 Dram Equivalent (1220 fps) of Bulk Smokeless in a 2 5/8" or 2 3/4" case with a modern transducer pressure of 8000 - 9500 psi.
Just before WWI: The "standard" U.S. 12g Field and Inanimate target load was 1 1/8 oz. shot with 3 Dr. Eq. (1200 fps) Dense Smokeless in a 2 3/4" case with a transducer pressure of 8,500 - 10,000 psi.

12g
1 1/8 oz. 3 Drams (1200 fps) of DuPont FFFg Black Powder (82 grains) is about 5000 psi.
1 1/8 oz. 3 Drams (82 gr) Curtis & Harvey's No. 4, T.S. Black Powder (similar to FFg) was about 6500 psi.
1 1/4 oz. 3 1/4 Drams Curtis & Harvey's No. 4, T.S. was about 8500 psi.

1 1/8 oz. 3 Dram Equivalent of BULK Smokeless was 6000 - 8000 psi.
1 1/8 oz. 3 Dr. Eq. of DENSE Smokeless was 8500 - 10,000 psi.
1 1/8 oz. 3 1/4 Dr. Eq. BULK Smokeless was about 8500 psi.
1 1/8 oz. 3 1/4 Dr. Eq. DENSE Smokeless was 9500 - 10,500 psi.
1 1/4 oz. 3 1/2 Dr. Eq. BULK Smokeless was about 11,500 psi
1 1/4 oz. 3 1/2 Dr. Eq. DENSE Smokeless was about 12,500 psi
The modern SAAMI 12g maximum 2 3/4" and 3" pressure is 11,500 psi

16g
1 oz. 2 1/2 Dr. Eq. (1165 fps) BULK Smokeless was about 7000 psi
2 3/4 Dr. Eq. (1220 fps) Bulk Smokeless about 8500 psi.

20g reported pressures varied significantly
7/8 oz. 2 1/2 Dr. Eq. BULK Smokeless was 8000-10,000 psi.
7/8 oz. 2 1/2 Dr. Eq. DENSE Smokeless was 11,000 - 12,500 psi.


PLEASE NOTE

Published Ballistic Tables by DuPont c. 1920s listed significantly higher pressures
(Numbers are estimated transducer pressures)

12g
1 1/8 oz 3 Dr. Eq. 9000 psi
1 1/4 oz. 3 1/4 Dr. Eq. 10,250 psi
16g 1 oz.
2 1/2 Dr. Eq. 9000 psi
2 3/4 Dr. Eq. 11,000 psi
20g 7/8 oz.
2 1/4 Dr. Eq. 12,500 psi
2 1/2 Dr. Eq. 13,750 psi


SAAMI allows the maximum average pressure for 12 gauge 2 3/4” and 3” shotgun shells to be 11,500 psi +/- 900 psi, with the maximum extreme variability not to exceed an uber-max of 12,500 psi +/- 900 psi or 13,400 psi.
 
#60 ·
In light of the recent differences of opinion expressed on the General Forum
viewtopic.php?f=2&t=432872
viewtopic.php?f=2&t=432969
and the Shotgun Reloading Forum
viewtopic.php?f=13&t=259371

I have edited my posts here so there can be no confusion as to what is my OPINION, and what is (I believe valuable and clearly referenced) historical INFORMATION.

My opinions are expressed on my (completely non-commercial) website, and I alone am responsible for the content therein. I hope it has been and will continue to be helpful
https://sites.google.com/a/damascusknow ... m/www/home
 
#61 ·
Prior to 1924, the Belgian and British Service (using) load for 12g 2 3/4" shells was 1 1/4 oz. / 3 1/4 Dram Eq. (1220 fps). The pressure of that load would have been about 8500 psi with BULK smokeless powder; with DENSE smokeless 9,500 - 10,500 psi.
2 1/2" shells were usually loaded with 1 1/8 oz. shot and 3 Dr. Eq. of BULK Smokeless with a pressure of 6500 - 7500 psi; DENSE Smokeless was 9000 - 10,000 psi.

During WWI the standard English 12g load was dropped by law (to conserve the supplies of lead and powder) to 1 oz. and 3 Dr. Eq. Bulk smokeless. After the War, 2 1/2" shells were generally loaded with 1 1/16 oz. shot and 3 Dr. Eq. Bulk or Dense smokeless powder.

In the 1925 British Proof House revisions, the 2 1/2" & 2 5/8" 12g service load was reduced to 3 Drams with 1 1/8 oz. shot with a mean max. service pressure of 3 1/4 tons = (converted using Burrard's formula) 9,682 psi.



After the 1924 Belgian Proof House revisions, the 12g max. service load was 600 kg/cm2 = 8534 psi + 10 - 14% by piezoelectric transducer measurement or about 9,600 psi.

Independent testing showed the 3 Dr. Eq. 1 1/8 oz. Old Style CF AA Winchester Trap Load to be 9,600 psi; AA Xtra-Lite 1 oz. WAAL12 8000 psi.

More information
https://docs.google.com/document/d/1F2s ... FU/preview
 
#63 ·
No one on the internet can tell you if YOUR gun is safe, with any load.
It should be marked 76mm/3" and carry 'TWO stars over PSF' marks for "Superior Proof"
More, but somewhat contradictory, information here
http://www.doublegunshop.com/forums/ubb ... 93b5d7fcf4
If you are inquiring regarding steel shot, that is a much more complex issue and you might post images of your gun's marks on the General Discussion Forum
 
#64 ·
Post-Western Super-X (1922) load pressures

Progressive Burning DuPont Improved Military Rifle (I.M.R.) Powders were introduced in 1914. DuPont Oval was developed for the 1922 introduction of Western Cartridge Company's 12g 'Super-X Field' 2 3/4" 1 1/4 oz. 3 3/4 Dram Equiv. shell. The Peters Cartridge Co. 'High Velocity', United States Cartridge Co. 'Ajax Heavies Long-Range', Remington Kleanbore 'Nitro Express Extra Long Range' (the boxes were marked "3 3/4 Drs. Equiv."), and Winchester Super Speed (also marked 3 3/4 Dr. Eq.) loads soon followed.
Western's 3 inch 'Record' with 1 3/8 oz. of shot was released in 1923.

Western Cartridge Co. never marked the Super-X 'Field' or 'Record' boxes with "Dr. Eq." stating only "Maximum Load". It is presumed that 12g 'Super-X Field' 2 3/4" 1 1/4 oz. was 3 3/4 Drams Equiv. or 1330 fps, and the 3" 1 3/8 oz. 'Record' was 1275 - 1295 fps (the speed of 1 1/4 oz. 3 1/2 Dr. Eq. loads). Other sources reported 1315 fps, presumably at 3 feet from the muzzle.

In c.1927-1935 Western Cartridge Co. pamphlets "Super-X The Long Range Load" by Capt. Chas. Askins the 12g "Duck Load" (not specified but presumed to be 1 1/4 oz. Super-X "Field") is described as 3 1/2 dram (38.5 gr. Powder; also not specified but no doubt DuPont Oval at 11 gr./Dram) at 1400 fps (at the muzzle rather than 3 feet) and 1000 fps at 40 yards, with a breech pressure of 3 3/4 tons or about 11,480 psi by Burrard's conversion.
3" Super-X Record with 1 3/8 oz. at MV 1400 fps with 4.25 Tons psi = 13,160 psi

From the 1928 edition of "Smokeless Shotgun Powders" by Wallace Coxe, ballistic engineer of the Burnside Laboratory of the E.I. du Pont de Nemours & Co. "DuPont Oval can be loaded with 1 3/8 ounces of shot in a 12-gauge shotgun to develop the same velocity and pressure as obtained with a load of 3 1/2 drams of DuPont Bulk Smokeless Powder or 28 grains of Ballistite and 1 1/4 ounces of shot. The relation naturally holds with other charges, but as DuPont Oval is used principally for maximum loads the comparison is more striking as it shows the possibility of using a heavy load with DuPont Oval that would be an abnormal load were it used with DuPont Bulk Smokeless, Ballistite, or other existing old-style types of shotgun powders."
Coxe reported 3 1/2 Dram Eq. 1 1/4 oz. loads (1275 fps) and 40 yard average fps:
NOTE: pressures were measured by crushers (LUP) and modern transducer measurement pressures would be 10 - 14% higher
DuPont Bulk smokeless powder - 11,700 psi, 943 fps
Schultze Bulk smokeless powder - 11,800 psi, 941 fps
28 grains of Ballistite Dense smokeless powder - 12,600 psi, 966 fps
Note all 3 are greater than the SAAMI 12g 2 3/4" recommended maximum
pressure of 11,500 psi.
40 grains of DuPont Oval Progressive Burning powder - 9,400 psi, 981 fps

From "Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics", 1933. The pressures (PSI by LUP) are for a 3 Dr. Eq. 1 1/4 oz. load + 10-14%
DuPont MX = 9,800 psi
DuPont MX Smokeless was a Dense Multi Base Powder introduced about 1930. 25.5 grains was a 3 Dr. Eq. and it was promoted as a 1 1/4 oz. Trap load. It was replaced in 1954 with IMR PB.
DuPont Bulk = 9,600 psi
FFFg = 9,000 psi
DuPont Oval = 8,700 psi
 
#66 ·
I've enjoyed reading the posts re this topic. I own dozens of old guns of all kinds. I have shot all but a few. I have a Hall rifle, Smith and Burnside carbines, Springfield muskets, both flint and percussion and an 1861 Springfield. I've got Lefever, L.C. Smith, Parker and Crescent shotguns. I've got some very old guns, Hardy shotguns c.a. 1845, frontier muzzleloading rifles c.a. 1840 and Colt pistols. I shoot them all. Some like the Parker GH and Ross MkII straight pull I first tied to a tire and touched them off with a long string. Some, the Hardy Bros muzzle loading shotgun and Pioneer rifle I shot when I was a kid and knew nothing about the dangers of shooting old guns. I just poured in BP from a powder horn until I decided to stop. Some I overloaded just for the heck of it. Some I had no idea how to load and just loaded them until the chambers were full....Colt percussion pistols and a Starr DA for example. I shot original duelers and screw barrel derringers. I have shot several original Sharps rifles a lot, some percussion and some cartridge, some shot extremely well and some shoot around corners. I shoot the old BP Mausers and a Danish Rolling Block. I own an old British fowler flintlock that I cannot bring myself to shoot. Had a gunsmith measure wall thickness of the barrel. I asked him if it'd be safe to shoot. He said, "Well, I don't know, but there's a lot of steel in that barrel."

I don't hesitate to shoot an old gun if it looks sound to me. Most of the shotguns people are concerned about in this thread are safe to shoot....unless you get a bad one.
 
#67 ·
Plain or Common Twist barrels on a c. 1890s J. Manton, Birmingham



Which survived 1200 BAR re-proof in 1992



12g CIP "High performance/Superior Proof"
Service 1050 BAR = 15,229 psi
Maximum statistical individual pressure 1200 BAR = 17,405 psi
Magnum proof 1320 BAR = 19,145 psi
 
#68 ·
Recreation, September, 1898
https://books.google.com/books?id=d4oXA ... -PA216&lpg
STRENGTH OF BLUE BARRELS.
A writer in RECREATION claimed that blued barrels, such as used on some of the cheaper American guns, are as strong as the imported twist barrels. My observations teach me this is a mistake. Anyone who is familiar with gun making knows the cheap blue barrels are all made from a good grade of rolled iron, which is bored at the factories where used. The grain of the metal must necessarily run lengthwise, and consequently will not stand the bursting strain which the same metal would stand if the grain ran in a spiral course. Besides, the twist barrels are made of the best Norway iron and steel, welded together in spiral form.
Again, the writer referred to says twist barrels are no longer made. This is a mistake. All barrel makers make them, although the old stub-and-twist, which were made of old horseshoe nails, are no longer made. I have it from so good an authority as Mr. Josette, of Pagnoul & Josette, the barrel makers of Liege, Belgium, that the twist or Damascus barrel will stand a much greater strain than the decarbonized steel (iron) barrel.
Anyone who frequents the Northwestern duck fields will see that many more cheap blue barrels than twist are burst with the heavy loads used for ducks.
I pin my faith to an Ithaca twist duck gun, and feel safe with 4 drams of Dupont's smokeless.
Northwest, St. Paul, Minn.

Maybe not

Bessemer, Decarbonized or "Plain" Gun Barrel Steel reported tensile strength was about 63,000 psi.
Marlin Model 1898 Slide Action Shotgun "Special Rolled Steel" was reported to be 66,000 psi

I tested 2 decarbonized specimens: 66,000 psi and 71,500 psi

My Twist samples averaged 53,300 psi; Crolle 54,700 psi
 
#69 ·
Howdy ya'll, N/E central Ga here. Just aqquired a Bridge Gun Co 12 ***** single with "choke" marked
on top of barrell, serial # A640503. Stock has a few dings, beauty marks, barrell has blueing still on,
bout 70% of barrell still blued, hammer/ trigger steel no blueing but no pits either. The only defects
were front sight ball snapped off and firing pin return spring gone, replaced with ink pen spring, yes I
know... The barrell has a mirror polish so might have been dressed, maker and date would be apprec.
but real question was this gun designed to shoot meduim brass shells or should I stick with low brass?
And yes no steel shot will go thru her. Again maker and date would be nice... Blessings
 
#70 ·
Bridge Gun Company was a tradename used on shotguns made for Sharpleigh Hardware Co. St. Louis, and were made by Crescent Fire Arms, Harrington and Richardson, and J. Stevens Arms Company.
Check this thread and you may be able to ID the maker
https://www.shotgunworld.com/bbs/viewto ... 5&t=447782

The gun should not be used with any load until it has been evaluated by someone with the interest, equipment and expertise to do so. If the barrels have been honed, the smith needs to measure wall thickness from breech to muzzle.
 
#71 · (Edited)
British standard service loads and pressures 1924-1954

1925 - 1954 12g barrel flats marked with chamber length and 1 1/8 or 1 1/4 oz.
In 1925, the 2 1/2" & 2 5/8" 12g maximum service load was reduced to 3 Dr. Eq. with 1 1/8 oz. shot with a mean pressure of 3 1/4 tons by LUP = 9,800 psi by Burrard's conversion of long tons to psi.
The 2 3/4" 12g max. service load was 3 3/8 Dr. Eq. with 1 1/4 oz. shot with a mean pressure of 3 1/2 tons = 10,640 psi. (Primarily for heavier "Waterfowl" guns)

Major Sir Gerald Burrard, The Modern Shotgun, Volume II, "The Cartridge", 1955 3rd Revised Edition pressures converted from Long Tons/ Sq. Inch at 1"
Standard 2 1/2" 12g loads were 1 1/16 oz.
12g 2 1/2" 33 gr. Nobel Smokeless (3 Dr. Eq.) with 1 1/16 oz. - 7,885 psi
12g 2 1/2" 33 gr. C&H Smokeless Diamond (3 Dr. Eq.) with 1 1/16 oz. - 8,288 psi
12g 2 1/2" 31 gr. Smokeless Diamond (2.8 Dr. Eq.) with 1 1/16 oz. - 7,179 psi
(Loads were designed for an "observed velocity" - average velocity over 20 yards - of about 1,050 fps = modern 3' from muzzle velocity of about 1200 fps)

Standard Load...........................Standard Service.....Max. Service

10g 2 7/8” 1 7/16 oz. 4 Dr. Eq............9,296 psi..........11,984 psi
12g 3” 1 1/2 oz. 3.57 Dr. Eq...............9,632 psi..........12,320 psi
(1 1/2 oz. with 3 3/4 Dr. Eq. is 1260 fps)
12g 2 1/2” 1 1/16 oz. 3 Dr. Eq.............7,952 psi..........10,640 psi
12g 2 3/4” 1 1/4 oz. 3 1/4 Dr. Eq.........9,296 psi..........11,984 psi
16g 2 1/2” 7/8 oz. 2 1/2 Dr. Eq............8,624 psi..........11,312 psi
16g 2 3/4” 1 oz. 2 7/8 Dr. Eq...............9,296 psi..........11,984 psi
20g 2 1/2” 3/4 oz. 2 1/4 Dr. Eq............9,632 psi..........12,320 psi
20g 2 3/4” 7/8 oz. 2 1/3 Dr. Eq............9,968 psi...........12,992 psi
28g 2 1/2” 9/16 oz. 1 7/8 Dr. Eq..........10,304 psi.........13,328 psi
.410 2” 5/16 oz. 7/8 Dr. Eq...................8,288 psi..........10,976 psi
.410 2 1/2” 3/8 oz. 1 Dr. Eq..................10,640 psi........14,000 psi
 
#72 ·
Thought I would add this information to the thread after finding this 1894 article in Forest & Stream

"Schultze" was one of the first smokeless powders, developed in 1862, and was first marketed in the U.S. by Von Lengerke & Detmold in 1887.
The American "E.C." & "Schultze" Powder Company was established in Oakland, New Jersey in 1890, and was purchased by DuPont in 1903. DuPont Bulk Smokeless was introduced that year.

Forest & Stream, November 24, 1894
"Gas Pressure or Bursting Strain"
https://books.google.com/books?id=19kwA ... =PA459&lpg
The proof-house charge of the American Testing Institution for a 12-bore gun develops a gas pressure of over 18,000 lbs. to the square inch. It is the same strain to which finished guns are put abroad. No gun would stand such a strain for any length of time. About 10,000 lbs. may be considered of touching the safety limit, and for some guns even is hazardous. A load giving about 8,000 lbs. pressure and less is better suited for the average gun and everyday use.
(The pressures were no doubt measured using LUP and modern transducer values would be 10-14% higher.)
Maybe this is where the frequently expressed 8000 psi load recommendation came from?!?

April 20, 1895 Sporting Life
"Shall Guns Be Tested?"
https://digital.la84.org/digital/collec ... 7/id/48142

July 27, 1895 Sporting Life
Call for Government Proof House for Nitro Powder Testing
https://digital.la84.org/digital/collec ... 7/id/48122

A.H. Fox 1911 Catalog
"Fox Proof Test means that every gun is tested with enormous over-charge according to the requirements of European governments."
(Under the 1896 British Rules of Proof, if 6 1/2 Drams Curtis and Harvey's "T.S." [Treble Strong] No. 2 and 1 2/3 oz. "soft" No. 6 shot was used for Definitive Proof, the pressure generated was [color:#FF0000]16,400 psi[/color]; if 90 grains = 6 1/2 Dram "E.C. No. 1" Bulk Smokeless Powder, 16,100 psi + 10 - 14% for either.)

From "Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics" by Wallace H Coxe; E.I. du Pont de Nemours & Co., 1927, p. 54
"It is generally conceded that a definitive proof should develop a pressure 25 to 40% greater than the service pressure to which it is expected the gun will be subjected."

LTC Calvin Goddard writing in "Army Ordnance" in 1934, stated that Hunter Arms proof tested 12g 2 3/4" chamber barrels at 14,300 psi + 10 - 14%.

A Parker Service and Proof Load table was published in the 1930s and reproduced in the The Parker Story p. 515. 12g 2 3/4" shell Service Pressure is 10,500 psi. Definitive proof used 7.53 Drams Black Powder and 2 oz. shot with a pressure of 15,900 psi + 10-14%, or more than 17,500 psi.

LTC Calvin Goddard reported the same numbers in "Army Ordnance", 1934. He wrote that Parker followed the SAAMI standards of that period: 13,700 psi proof, 9500 psi service for 2 5/8" chamber; 15,900 psi proof, 10,500 psi service for 2 3/4" chamber (by LUP) + 10-14%

Parker GHE SN 221278 1927 D3 3 Iron damascus with the "PARKER BROS. OVERLOAD PROVED" stamp which first appeared in 1925.



Ithaca advertisements stated that barrels were proved with a "double charge of powder and 1 1/2 times the normal shot load"; or (possibly) 6 1/2 Drams Black Powder with 2 1/4 oz. of shot if the standard load was 1 1/8 oz. shot and 3 1/4 Dram Eq.
Jack O'Connor wrote in Outdoor Life in 1942 that Lew Smith, President of Ithaca Gun Co. stated the Proof Loads were 17,500 psi + 10 - 14%

1911 Ithaca Gr. 1 Flues with "NITRO POWDER PROVED"



Modern 12g and 16g 2 3/4" and 3" SAAMI Recommended Proof Pressures
http://saami.org/specifications_and_inf ... tshell.pdf
If a manufacturer uses a SAAMI proof loads, then the gun will be proofed by a lot of no less than 10 shots of ammo loaded to a maximum proof pressure of 20,500 psi +/- 900 - 4600 psi, or uber max of 25,100 PSI; and, will be similarly a MINIMUM average proof pressure of 19,000 PSI +/- 900 - 4600 psi for an absolute minimum proof of 14,400 PSI.

The powders used in proof loads are not specified on the SAMMI site
 
#73 ·
Mr. Hause:
As usual, you are a wealth of information. I will read it in more detail later but I have seen some of it. I am told that most blow ups are the result of barrel obstructions, as some of your data seems to indicate. Fortunately, I think you will agree, most guns will survive much more pressure than they should ever see. They usually start falling apart before they fail completely. However, it only has to dramatically fail once, as your photographs suggest, to ruin your whole day. I don't & don't suggest that anybody else should not take the precautions you recommend. Nobody ever got hurt from being cautious! Structures & guns are designed with what engineers call a safety factor. When I am dealing with something that can hurt or kill me, personally, I like a really big safety factor.
Thank you for sharing this with us!
I just realized how long this post has been going on! I apologize for repeating old material but it is a topic that is always of interest!
 
#74 · (Edited)
I went back through this thread and found a number of the charts had been re-formatted, and think those are now corrected. And I'll add this

John Brindle, author of Shotgun Shooting: Techniques & Technology published a review of Proof and Service pressures in Part 5 of his series in The Double Gun Journal, “Black Powder & Smokeless, Damascus & Steel”; Volume 5, Issue 3, 1994, “Some Modern Fallacies Part 5”, p. 11.
His estimated post-1954 but pre-CIP standard pressures by LUP converted to piezo transducer PSI

.........Standard Service....Max. Service......Proof
12g 2 1/2”.....6,800 psi......8,800 psi..........12,250 psi
12g 2 3/4”.....7,800 psi......9,800 psi..........14,050 psi
(CIP 2 3/4”)..10,733 psi....12,328 psi.........13,489 psi
16g 2 1/2”.....7,300 psi......9,300 psi...........13,150 psi
16g 2 3/4”.....7,800 psi......9,800 psi...........14,050 psi


Great Britain adopted the 1969 Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives standards March 1, 1980 but continued using Lead Crushers to measure pressure until 1989.
The CIP transducer “Maximal Statistical Individual Pressure” is 850 BAR = 12,328 PSI for a “Maximal Average (Service) Pressure” of 740 BAR = 10,733 PSI, and “Mean Proof Pressure” of 930 BAR = 13,924 PSI.
900 BAR is for a “Maximal Average (Service) Pressure” of 780 BAR = 11,313 PSI and Proof pressure of 1020 BAR = 14,794 PSI.
 
#75 · (Edited)
SPANISH proof and service loads pre-CIP (c. 1970)

850 kg/cm2 proof was commonly used for entry level Basque 12/70 guns of the 50's through the early 70's. Better grades carried 900 or 1000 kg/cm2 proof with some 12/70 pigeon guns 1200 kg/cm2.
Kg/cm2 as determined by lead crushers is a different measure of pressure than BAR as determined by modern piezo transducers.
BAR was used only after the CIP standards were adopted


Under the Belgian Proof House revisions of 1924
12g guns were proved at 900 kg/cm2 for a 600 kg/cm2 = 8534 psi maximum SERVICE pressure;
20g were proved at 1000 kg/cm2 for a 670 kg/cm2 = 9530 psi maximum SERVICE pressure
+ 10 - 14% by piezoelectric transducer measurement
That would be a service of 2/3 of proof.

850 kg/cm2 proof = 12,090 psi for a service pressure of 566.6 kg/cm2 or 8060 psi BUT as measured by lead crushers, so by modern piezo transducers the pressure would be + 10 - 14% or about 9000 psi
900 kg/cm2 proof = 12,801 for a 600 kg/cm2 = 8534 psi service pressure + 10 – 14%
or about 9500 psi
1000 kg/cm2 proof = 14,223 psi for a service load of 9,473 psi + 10 – 14% or
about 10,500 psi
1100 kg/cm2 proof = 15,645 psi for a service load of 10,430 psi + 10 - 14% or
about 11,500 psi
1200 kg/cm2 proof = 17,068 psi for a service load of 800 kg/cm2 = 11,380 + 10 – 14%
or about 12,500 psi

(If CIP transducer BAR - The Maximum Statistical Individual Pressure of 850 BAR = 12,328 psi is for a Maximum Average (SERVICE) Pressure 740 BAR = 10,733 psi)

British shell boxes are marked
These cartridges are suitable for use in:
70mm case length: Guns with a chamber length of 2 3/4" or longer, nitro proofed to a service pressure of 3 1/4 tons per square inch (900 kg per square cm)
67 mm case length: Guns with a chamber length of 2 1/2" or longer, nitro proofed to a service pressure of 3 tons per square inch (850 kg per square cm)
SO the estimated Spanish service pressures are very similar to the post-1954 British Rules of Proof tons:
850 kg/cm2 proof is equivalent to 3 tons service = 8938 psi
900 kg/cm2 is 3 1/4 tons = 9682 psi
1000 kg/cm2 is 3 1/2 tons = 10,427 psi
1200 kg/cm2 is 4 tons = 11,917 psi
 
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