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 Post subject: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 12:17 am 
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Black and Nitro Pressure Tests, 1897

I’ve been looking into the need to use Blackpowder in Damascus Barreled Shotguns and why Damascus has a reputation for blowing up. Thought I'd post some info that I haven't seen before. Hope It's useful.

The following charts were taken from an article: ‘Powder Pressures at Different Parts of the Gun Barrel’ in the book ‘Sporting Guns and Gunpowder’, published by ‘The Field’ in London in 1897. You can find it by searching Google Books. Since gun barrels were failing at that time I find it sheds some light on the reasons why.

The pressure curves were measured in a 12 Ga Shotgun firing 1 1/8 Oz of No 6 Shot, all at 1220 ft/sec muzzle velocity (except for the BP Proof curve). They didn’t specify the barrel type used but it was almost certainly some version of Damascus since it was still considered the best.

The first graph shows the Blackpowder pressures.

Image

The top curve is the Proof pressure results for 6 ½ Drams (equals about 175 Grains) of ‘Proof’ Blackpowder with 1 2/3 Oz of Shot (Nitro Proofing was optional at the time). It was included for safety margin comparisons.

The next three Blackpowder curves are for: 72 Grains of No 2 (very fine), 82 Grs of No 4 (coarser) and 84 Grs of No 6 (coarsest). The No 2 Blackpowder was tested for comparison purposes; it is too fine to be used in Shotguns. Its’ high surface area causes it to “burn” rapidly, increasing breech pressures. It was typically used to prime Flintlock pans.

The No 4 and 6 were typical Blackpowders used in shotguns of the time. I expect they were similar to the Fg or FFg designations of Blackpowder used in Rifles. A reproduction 1895 Montgomery Ward catalog shows Dupont Blackpowder grain sizes. Their Fg ‘Rifle’ powder looks midway in size to their No 5 and No 7 ‘Choke Bore’ grades. They should still be similar to Fg and FFg produced today.

The second graph shows results for four Nitro powders: 32 Grs of Ballistite, 34 Grs of Walsrode, 38 Grs of Cannonite and 42 Grs of Schultze. Note that the Nitro Powders of the time required approximately 1/2 the weight of Black to obtain similar pressures and velocities, that is they were about twice as powerful on a weight basis.

Image

Note that three of the Nitro Powders (Walsrode, Cannonite and Schultze) had pressure curves very similar to the two typical Shotgun Powders (No 4 and 6). I expect that they have similar burn rates to the shotgun powders used today. Ballistite had a peak pressure closer to No 2 Black. I expect it is closer to a faster modern powders typically used in pistols.

There are several others articles in the book that addressed the rash of blown barrels that had occurred in the prior several years. They concluded that most were due to a lack of knowledge or care in loading the new Nitro Powders. Problem shells were found with a ‘3 Dram volume’ of Nitro powders. That would be a severe overload for the pressure sensitive Nitro powders. They typically require ½ the weight of Blackpowder to generate similar pressures. The ‘3 Dram Volume’ would be approximately a double load of Nitro powder that could easily exceed Proof pressures. (The quotes on ‘3 Dram volume’ are there since a Dram is actually a weight; dippers that held about three Drams of Blackpowder were often used as a typical volume measurement for BP.) Even using a single volume measurement for all Nitro powders was problem since these powders varied significantly in density and had to be weighted first to find the correct volume to use for each powder.

Schultze and Walsrode were sold in the 1895 M.W. catalog. Walsrode had a warning that it should only be used in ‘high grade’ guns and that it shouldn’t be overloaded. They sold special powder measures for its use. Unfortunately there wasn’t any indication in the catalog as to what ‘high grade’ guns were. Steel barrels were mostly used on the lower costs shotguns, many of the Damascus barreled guns said something like ‘bored for Nitro or Black powders, will shoot either kind’, which is meaningless to me, and the fancier Damascus patterns were actually often weaker that the plainer less expensive ‘Laminates' and 'Twists’.

Other over-pressure causes in the book: using too hot of a primer, using some BP as a primer to ensure reliable ignition of the hard to ignite Nitro powders, drying the powders, variations in the manufactures powder plus the usual range of plugged barrels. There was also a tendency for handloaders to use as enough Nitro powder to match the recoil of Blackpowder in the belief that the high recoil meant the gun was shooting ‘hard’ enough, which resulted in overloads. There were no indications I could find that Damascus had any more or less failures than the steel barrels used at that time.

They also measured recoil energy and found the Nitro powders produced about twice the recoil that could be accounted for by the shot alone and the BPs generated about three times the recoil of the shot alone. This is due to the recoil generated by the gases. When the projectile leaves the muzzle the gases accelerate to velocities well above that of the projectile and yield a higher proportion of recoil than would be expected by their weight alone (recoil energy = weight x velocity x velocity). The higher weight of the Blackpowder yielded a higher recoil than the Nitro powders.

Of course the pressure at the breech actually starts at zero and climbs to a peak as the projectile passes down the bore but the mechanical Lead Crusher gauges used couldn’t record the initial low pressures; they show the initial as greater than zero. (The pressure at the breech has to increase as the down bore pressure increases or else the gases wouldn’t be pushed down the bore. The mechanical crusher gauges in the breech end can only measure the peak pressure they see, not the pressure vs. time curve, so they have to register the highest down bore pressure.) The gauges located past the peak pressure could register actual maximum pressures at their location. (Modern strain gauges measure the breech pressure versus time during the entire firing event so they can measure the initial pressures. They then calculate the projectiles’ location and generate a Pressure vs. Distance curve.)

There are measurements in the book that do give indications of the initial pressure rise. Velocity measurements in the first few inches of the breech show that the Blackpowders accelerated the shot faster than the Nitros did, so they must be generating higher initial pressures at the breech. This was thought to be due to the lower ignition temperatures of BP, which allowed them to burn quicker initially. I don't put much importance on higher initial breech pressures since, as mentioned above, breech pressures have to rise at least as high as the highest down bore pressures.

I’d be careful comparing these pressures to modern measurements since even newer Lead Crusher gauges are likely to be built and calibrated to different standards. In any event, the Proof pressure shows a peak of 4.5 Tons (Metric) or 9,900 PSI. Peak pressures for the two coarser BPs are about 2.2 Tons or 4,840 PSI and the three lower pressure Nitro powders are about 1.8 Tons or 3,960 PSI. I expect modern pressure measurements would give results higher than those shown. For example a pressure of about 10,000 psi is required to get velocities in the 1,200 Ft/Sec range with 1 1/8 Oz of shot. The quoted 3,690 PSI is way too low compared to modern pressure measurement techniques. But these results should be precise enough for comparisons between each other; they were repeated many times to get reasonable statistical results.

Based just on these results I’d opt for Nitro powders: they have lower pressures which places less strain on the barrels, less recoil to break stocks and loosen actions, they burn cleaner, cause less rusting and have no smoke to interfere with the second shot (not that I ever need one!). No wonder BP went out of fashion! But I still like the big boom and smoke.




Last edited by Bob S on Fri Aug 19, 2011 1:17 pm, edited 11 times in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 8:50 am 
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Bob, the graphs and data presented are over 100 years old, and are for black powder currently unavailable (at least here in the USA.) Most smokeless powders currently available have working pressures (published loadings) DOUBLE black powder pressure. Point is, you need up-to-date data on currently available black powder versus (as an example) low-pressure smokeless powder (i.e. IMR PB). And that's just PART I.

For PART II, the gun has to be thoroughly inspected by a COMPETENT gunsmith to assure no intergranular corrosion has taken place, and the arm is safe for firing.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 11:46 am 
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There are very good reasons for not shooting Damascus barreled shotguns with any powder, in my opinion, but indeed there is a fraternity that vehemently disagrees. They shoot them regularly with no negative consequences.

Why do they have a reputation for blowing up? There are those who say it's an old wives tale, me I think shooting them is tempting fate. Look at how Damascus barrels were made say 100+ years ago. Do you think the metallurgy and welding techniques were all that great and sophisticated then? Why do old "fluid steel" barrels rupture too? Simple, the fluid steel barrels weren't all that good either. Metallurgy has come a long ways in a hundred years. Damascus barrels leave the possibility and/or probability for rust and corrosion to form in tiny little seams, voids and crevices over a bunch of years in the welds of the Damascus barrels. Will that increase the structural integrity of the "weld"? Face it, a damascus barrel is nothing but a long hollow weld! If you think 100 year old welds with several thousands of psi of pressure in your hands and by your face is a good thing, by all means have at it. I think reproofing tells me nothing but the fact that the gun didn't blow up with the proof load. I believe damascus barrels just by the nature of the beast have an inherent potential for disastrous response to pressure, especially more or less instantaneous pressure rises. The last shot didn't blow the barrel up, but what about the next one?

Go to the General forum if you haven't yet and wait for Eugene Malolly I think he is and some others who do shoot those beauties to tell you the real story.

BP

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 2:41 pm 
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All input is appreciated but I was hoping to avoid repeating all the opinions on the safety of Damascus. Any Newbie that Googles ‘Damascus Barrel’ will find Ad-Nauseum "reasons" that Damascus is "dangerous", almost all of which have no facts to back them up.

In the meantime I’ll try to keep posting facts. They’ll probably be mixed with my opinions but I’ll assume the reader has the wits to tell the difference. Hey, I might even try posting ‘My Top-Ten Favorite Damascus Myths’.


Last edited by Bob S on Fri Jul 19, 2013 7:55 pm, edited 2 times in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 3:03 pm 
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Damascus vs. Steel Barrel Tests

Some information on vintage Damascus and Steel shotgun barrels tested with Blackpowder. Taken from 'Sporting Guns and Gunpowder' by Frederick Toms, 1897. Same book as mentioned above.

Background:

The tests were done to compare Damascus with (then) modern Steel,
The tests were designed to determine how much of an overload was required to rupture the barrels, not just deform them,
Both the Steel and Damascus barrels were finished to the same dimensions,
They wanted the barrels to fail near the breech (most dangerous) so they increased the shot charges first to maximize the breech pressure and then they increased the powder charge.
They STARTED with 6 1/2 drams (the normal proof charge of Balckpowder) and 2 Oz of shot in a 12 gauge! About twice a normal load.

From the book:

"Fig. 3 shows the unbrazed Damascus barrel. With this the first indication of distress was seen after firing test No. 23, when the charge was 7 ½ Drs. of powder and 12oz. of shot; it was then somewhat rivelled and bent. In the next round the barrel commenced to bulge at 6in. from the breech; but it held on for six more trials, and collapsed at test No. 30, with 11 Drs. of powder and 12oz. of shot."

"Fig. 1 represents the remains of the unbrazed barrel of Siemens-Martin steel, which burst with test No. 40, when the charge used was 16 Drs. of powder and 12oz. of shot. This barrel first exhibited signs of distress with trial No. 26, when the charge was 9 Drs. of powder and 12oz. of shot, the tube then showing a slight bulge at 7in. from the breech, and being somewhat rivelled and bent near the muzzle; nevertheless, it underwent thirteen more tests before the actual fracture occurred."

My conclusions:

Both materials withstood EXTREME loads. The testers didn't even machine chambers into the barrels since they knew the loads would not fit in any reasonable chamber volume; they installed breech plugs and fired them like muzzle loaders. The Barrels bent to such a degree with the heavier charges that they had to be straightened before they could be loaded for the next test. When the charge was increased to 12 Oz of shot, with the initial 6 1/2 drams of powder, the charge stuck in the barrels, plugging the expanding powder in the barrel. After removing the shot and cleaning, they had to increase the powder loads to force the shot out of the barrels.

The steel withstood the highest charge (16 drams vs., 11 drams for Damascus).

Note: the steel and Damascus used were among the highest rated in prior bulge testing (increasing loads until they bulged 0.010" on the diameter). I couldn't decipher the un-decipherable names of the Damascus and Steels types. The descriptions used gave little information about their strengths, composition or post treatments; things that are considered critical to modern steel specifications

It's unclear to me if the barrels that performed poorly in the prior 'bulging' tests would necessarily perform poorly in the burst tests.

Other thoughts:

From the drawings in the book, the modern steel seemed to shatter into shrapnel while the Damascus appeared to fail with less pieces (it's probably more ductile with less tensile strength than all steel, hence the lower failure pressures and less shrapnel). Damascus also gave earlier failure warnings by bulging sooner. I'd prefer to be holding a ductile barrel that tears rather than one that shatters.

The authors believed that these multiple tests at continuously increasing pressures disproved the old fear that Proof testing could damage the barrels and cause them to fail afterwards. That's true since to pass Proof testing there can be no bulging/streching. But the pressures used in this test must have be well above proof pressures; they streched the barrels, repeated streching can cause steel to fail by 'fatigue'.

Today’s steels may be even stronger than those of 1897. But it is by no means certain. Steels were well developed by this time; tool and ball bearing steels were available and the heat treatment methods were well known. The last big steel development was the production of Stainless Steels but that occurred in about 1915. This doesn't necessarily mean that modern barrels are stronger, even assuming the modern manufactures use stronger steels; they may be of lesser wall thickness than the older barrels to save weight. Vintage American Doubles usually had heavy walled barrels at the breech to handle heavy charges, the English preferred lighter, and therefore thinner, barrels.

I have no problem shooting smokeless shells with Damascus. I check barrel thickness, look for obvious corrosion and hold the barrels by the lump and rap them, if they ring the solder holding the tubes together is probably OK. I 'proof test' them first with the highest load/velocity shells that fit the chamber using a string from a distance. If I still have a gun, I shoot only low-pressure shells and it's usually all fun from there.

I’m not sure how much luck you will have following the advice to get a gunsmith to inspect the gun and give you an OK to shoot it. When I buy old guns from local shops, which are owned mainly by ‘gunsmiths’, I almost always get the old routine ‘you’re not going to shoot it are you?’. Even if you find a smith who knows Damascus they are not likely to give you an OK and risk a Law Suit if they are wrong. They should however point out serious flaws, if any.

Note: common chamber lengths around 1900 were often less than todays 2 3/4" or longer. Most people reccommend you don't shoot the longer shells in the shorter chambers; the crimp may not be able to open fully, increasing chamber pressure. Your gunsmith should be able to lengthen the older chambers and advise you if there is enough barrel thickness to do this. (The loaded/crimped shell is shorter than its nominal lenght before it is fired and should fit within the chamber length after it is fired, eg, a 2 3/4" shell will actually be shorter than 2 3/4" before it is fired, the chamber measures 2 3/4".)

My best advice, which may be worth what you are paying for it: if you aren't comfortable that you know what you are doing, then don't do it.

I worry more about the receivers of older guns, they were made from soft low carbon steel so they could be hand formed and finished. After finishing they were case hardened to provide some scratch resistance on the surface but that still left a soft/weak receiver. If you shoot them with any but the lightest loads the barrels could pull away from the breech face, a common but not deadly weakness in older shotguns. The stocks can also break with high recoil (BP gives higher recoil that an equivalent load of Smokeless). If the wood has shrunk, which it will likely do after 100 years, the bedding between the stock and action will loosen, allowing the reciever to slam into the stock under recoil. The top tang and sidelocks, if it has them, then act as wedges to split the wood. Best to glass bed the stock/action and relieve the wood at the rear of the tang/locks if you value the wood.

If you are worried about barrel failures it doesn’t seem likely that you will shoot them; it tends to ruin all the fun if you are crouching in fear when you pull the trigger.

I suspect plugged bores are the most frequent cause of failures, not inherent barrel weakness. Any barrel can rupture when it is plugged near the muzzle. Overloading handloads, on purpose or on accident, may be second most frequent cause. As I mentioned, I would rather have a soft Damascus barrel bulge than have a hard Steel barrel burst.

Don't get me wrong, I wouldn't shoot a Damascus or Steel barrel with flaws anymore than I would want to shoot a gun with a double charge of Smokeless. And you can't always tell if the Barrels are safe; they could have hidden corrosion between the Barrels. Magnafluxing or even X-Rays may not be able to see between the barrels (same with steel barrels). Full proof loads are the best in my opinion.

I worry more about Muzzle Loaders, Damascus or not. You can’t see inside the breech, the place that is hardest to clean and the most likely to rust. Removing the breech plugs in a SxS Muzzleloader to inspect the barrels may require a complete dismantling of the barrels. Specialized barrel thickness gauges or bore scopes may help if you have access to them.


Last edited by Bob S on Mon Mar 31, 2014 8:03 pm, edited 8 times in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 3:17 pm 
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Well, here are some facts -

Black powder loads have a different pressure curve than smokeless, where the chamber pressures run VERY high (in the 8,500 to 11,500 psi range, compared to the 5,500 to 6,000 psi range for black powder loads. Nitro powders today in the US are "progressive burning" and bear no resemblance to the powders in your referenced data.

And yes, I have fired my old hammer 12 ga. SXS with a 2 9/16" chamber using 1 oz. 3 dram of black powder in loads I assembled myself. And I examined the gun VERY carefully before using. (But I was still uncertain or positive of the outcome, as I couldn't really see inside the metal microscopically) And yes, it was a lot of fun at the skeet range.

And yes, I am a graduate chemist and also have degrees in chemical engineering and electrochemical engineering with a lot of metallurgy background as well.

You didn't give any info - What kind of gun is it? What does the bore look like? What does the INSIDE of the receiver look like from a corrosion viewpoint? Some are a lot better than others, and have received proper care and cleaning. But a large majority were cheap guns made in Belgium (among others) and used (and abused) with minimum cleaning, if at all.

SOME damascus barrels and guns are fine. MOST are not! We have NO WAY of knowing what you have.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 3:21 pm 
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Bob S,

Sorry if you took offense from my post, wasn't intended. I thought I was answering the question you made in your very first sentence. I guess not!

After reading you two posts I'm a bit confused as to what you are really asking here? Anything? Nothing! Just supplying information that is over 100 years old?

Anyway, I know nothing whatever about damascus barrels on shotguns. To me they are all wall hangers or safe queens. I hope you find whatever information you are looking for.

Maybe do a search here on the subject of damascus barrels, find names of some of the more knowledgeable posters, PM some of them, maybe they can lead you to your goal? There have been some very extensive and heated discussions here in the past. I'd try the search if I were you, you might be amazed at what or who you'll find!

Duty calls, got to run!

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 4:38 pm 
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BobK:

Any documentation on your pressure claims? If not, I should be posting some soon. Maybe facts can lift the subject above myths. As a ChemE you should know science requires data.

I have close to a dozen SxS shotguns, most of them Damascus. I've refinished, smithed, and shot most of them and still have all ten fingers. If you read my post you would see that I was simply providing information that I thought would be of interest to others.

BTW: your suggestion that a 'Smith should inspect the barrels for Intergranular Corrosion is a bit useless: 'Smiths don't have the sample preparation or the Microscopic equipment needed to look for Intergranular Corrosion, only Metalurical Labs are equipped to do so. It also requires a piece be cut from the Barrel for preparation and examination; not likely you'd want to shoot a barrel with a hole cut in it! Besides, Intergranular Corrosion only occurs in Corrosion Resistant metals in extremely corrosive environments; such as S.S. in flowing acids.


Last edited by Bob S on Fri Jul 19, 2013 7:58 pm, edited 2 times in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 6:13 pm 
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BobS,

You need to get some back issues of The Double Gun Journal.

A lot of the data cited in this thread is outdated. I'd bet your 19th century data was based on "brisanse" sp? testing vs. actual pressure transducers that are used now. I'd trust the actual transient responses from the new technology over the derived.

With that, the gentleman who did the series of articles in the DGJ performed tests with state of the art technology and performed enough tests to get statistically significant results. He also tested Parker barrels to failure, and the results are impressive.

The bottom line as I recall was that for equivalent loads, Blue Dot has an identical pressure vs. time curve as black powder. These pressures were measured at the chamber, just in front of the chamber, approximately where the forearm is mounted, and at the choke.

So, the smokeless powder vs. black powder myth depends on the particular smokeless powder and is not the across the board answer.

I know guys that shoot Damascus Parkers regularly with smokeless (using the guidelines of the articles in DGJ). One assisted in some of the testing.

The common thread is that they KNOW what they are doing. They meticulously inspect the weapons and measure barrel thickness. They are very careful with their home rolled loads. They reduce the risk to that of shooting a fluid steel barrel.

I personally think that a lot of the Damascus issues were due to shooting 2-3/4" in 2-9/16 chambers, shooting high pressure/high velocity loads that exeeded the P/t curve of Blue Dot, and barrel obstructions.

There are too many guys shooting these old guns and shooting them frequently enough to blame Damascus alone.

So, do a little more research and enjoy your gun.

Regards,

3drahthaars


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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 9:25 pm 
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'Drahthaars'
Nice dogs! I have an English Setter myself.

The 1897 data is a bit outdated! It's main purpose is to give some background information from the time that Damascus got a bad rap. I thought the equal pressures between BP and Nitro at the time was interesting.

As I mentioned in the first post: pressures were taken with Lead Crusher Gauges, they won't correlate to modern tests, the difference between Crushers and Strain Cells was mentioned.

Read more: viewtopic.php?f=13&t=259371#ixzz1OGeJv24y


Last edited by Bob S on Fri Jul 19, 2013 8:01 pm, edited 1 time in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 10:35 pm 
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The first of my "Top Ten Damascus/Smokeless Myth Busters":

1) “Modern Blackpowder is different/ more powerful than it was 100 years ago.”

From Wikipedia: The current standard composition for the black powders that are manufactured by pyrotechnicians was adopted as long ago as 1780. Proportions by weight are 75% potassium nitrate (known as saltpeter), 15% softwood charcoal, and 10% sulfur.

Last I checked DuPont was still making Goex. It has stricter shipping requirements than Smokeless due to its’ lower ignition temperature so it may be harder to find.


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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 11:04 pm 
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Bob:

I'm having a hard time believing that with your claimed scientific background you are basing your conclusions on tests performed in the 1890s and information obtained from Wikipedia (hardly a trusted scientific source).

If I am going to risk life and limb shooting a Damascus-barreled gun (yes, I do have several of them...all hanging on the wall), I would certainly want better "data" than that obtained from those two sources.

YMMV

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Fri Jun 03, 2011 11:55 pm 
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Some pressure curves newer than 1897:

Image

Image

They are from a 45-70 rifle. The originals used BP cartridges. They are for comparisons between BP and Smokeless only. Dont try them in Shotguns!

The 'Rnd' is just the shot number. 'Vel13' is the muzzle velocity in Ft/Sec. Don't know what 'Prf' is. 'Peak' is the peak pressure if you add two zeros to it. 'Rise' is the time, in milliseconds, the pressure takes to take to go to the peak pressure (from something like 20% of peak to 80% of peak pressure, lower times =faster rise rate).

Velocities are all in the same range which provides a good basis for comparison.

The Smokeless IRM4759 shows a lower peak pressure and slower pressure rise than the FFG and FFFG Blackpowders with equivalent velocities. Note that this test used a 410 gr bullet while the others used 500 gr bullets. If the heavier projectile were used, the pressures and rise rates woud have increased some.

The Smokeless 'Trail Boss' shows about twice peak pressure and almost twice the rise rate. It also had the lowest velocities. Not a good choice! It's for handguns.

You can find more info on these curves at: http://www.levergunscommunity.com/viewtopic.php?f=1&t=27410
"KirkD" seems to have the most knowlegable posts.

From a Post at:
http://www.16ga.com/forum/viewtopic.php?t=10078&postdays=0&postorder=asc&start=0

"The Double Gun Journal, Volume Seventeen, Issue 4, Winter 2006. "Wall Hanger Rendezvous & The Slow Powder Myth" pages 39-40 by Sherman Bell.

Sherman Bell pressure tested a 1 1/4 ounce load of 3 3/4 drams GOEX FFFg vs. Blue Dot both at 1240fps - results:

@ 1" from breech - black = 5900psi Blue Dot = 6000psi
@ 6" from breech - black = 4100psi Blue Dot = 4300psi
@ 12" from breech - black = 2100psi Blue Dot = 2300psi

These pressure values are virtually identical at each point and should pretty much shoot down talk about the different pressure curves of black and smokeless.

It's worth reading the entire article because he goes into more detail debunking the myth that smokeless develops too much pressure down bore."

Looks like a good choice for most any shotgun!

These may be the loads that '3drahthaars' was referring to.

There is more information at that ULR on commercialy available light loads with pressures from about 5,800 to 6,800.

Before someone corrects me: don't try this at home, I'm only trying to put some factual data to the Damacus shooting issues.


Last edited by Bob S on Tue Aug 02, 2011 9:42 pm, edited 3 times in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 12:52 am 
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OldSkeeter:
Wow! Tough Audience!


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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 7:52 am 
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The Lyman book on reloading with Black Powder had shotgun loading data in it, along with "LUP" pressure readings, it was published in the mid '70s. There were ALSO later editions.

Sam Fadala published quite a few Black Powder handbooks and had shotgun loads, pressures, and were for current and MODERN US-manufactured powders, including black powder substitutes.

There is a PLETHORA of shotgun loading data from every powder manufacturer out there and it ALL has pressure data. And these are ALL CURRENT!!

So get your head out of the sand, spend a few bucks on some GOOD and CURRENT reading, use your computer and get into the 21st century!!

I'm out of this discussion..... It sounds more like a troll conversation!

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 2:07 pm 
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I don't have any damascus guns but if I did, I wouldn't hesitate to shoot them with the appropriate loads. Personally, I would trust the real experts, i.e. the British (Bermingham I believe) proof house. Damascus guns are reproofed for smokeless loads on a regular basis & there have been 3.5" damascus 10 ga. doubles reproofed for 3.5" smokeless loads in fairly recent years. To answer the question, what is safe in a damascus gun?, the answer is the same for any firearm, it depends on the gun. Pressure doesn't have a shelf life. Since most people can't or don't want to pay the cost of sending a gun to Bermingham for testing, the next best thing is to try to duplicate what they do. Any gun that will endure the abuse stated above is not going to rupture with a normal load. The service load is normally a percentage of the proof load which depends on which proof house is doing the proofing. Black powder has been shown to generate over 20,000 PSI (from the double gun journal). I don't know how much pressure 16 drams of BP & 12 ounces of shot would produce. Maybe it is in the chart shown above. I do know that I would not shoot it in any of my 3.5" 10 ga. mag. SXS's. I personally like moderate loads with any type of powder. What kills me is that you often hear gun dealers tell you to only shoot low brass & don't shoot buckshot in old guns. All shells of a particular ga. & length are loaded to the same pressure standards in the US. A 12ga. 7/8 oz. low brass lead load can generate as much pressure as a 3" magnum buckshot load. SAAMI standards call for a max. of 11,500 psi in all 12 ga. loads except for the 3.5" mag.


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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 3:47 pm 
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BobK wrote:
I'm out of this discussion..... It sounds more like a troll conversation!

Thanks!! It's unfounded claims like yours that have lead to the myths about Damascus, BP and Nitros in the first place.


Last edited by Bob S on Fri Jul 19, 2013 8:06 pm, edited 1 time in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 4:10 pm 
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Bob S wrote:
OldSkeeter:
Wow! Tough Audience!
Quote:
I'm having a hard time believing that with your claimed scientific background you are basing your conclusions on tests performed in the 1890s and information obtained from Wikipedia (hardly a trusted scientific source).

Do you have any better sources for 1890s test data or information on the history of Blackpowder? If so please help out and post it. Vague negative comments aren't helping.
Not sure what conclusions you think I have come to. Please let me know.
Not sure why you question my 'claimed' scientific background. If I didn't have such a deep belief in the kindness of the human heart I could take that as an insult!
Quote:
If I am going to risk life and limb shooting a Damascus-barreled gun (yes, I do have several of them...all hanging on the wall), I would certainly want better "data" than that obtained from those two sources.


If you have any 100 year old powder I'd save it for its' collector value. Hope you didn't think I was suggesting you shoot it. I hadn't even posted any usable loading data before you said you wouldn't use it (??!!?). Seems like you've already made up your mind not to shoot your guns; why are you reading this post?

If you missed this, I'll repeat it: I'm just posting hopefully useful information on the question of shooting Damascus/Smokeless.

You have a God given right to hang your guns any where you want. I'm sure you'll extend me the same courtesy.


I, too, think you are a troll! Either that, or someone trying to feed his ego.

Dredging up 120-year-old test to say you are "just posting hopefully useful information on the question of shooting Damascus/Smokeless" would lead many to believe that this outdated information indicates that shooting smokeless loads in Damascus guns is OK. Even hinting that this might be the case is a disservice, especially to less experienced shooters who might actually believe this stuff.

"One Troll down, indeed!" I'm done feeding the troll.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 4:34 pm 
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Joined: Wed Jan 12, 2011 9:55 pm
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geometric:

Good info!

Not sure if my Fear Factor would even let me get close to a 10 Ga 3.5" SxS Magnum. Didn't know they made such a beast.

In the 1897 book I've been quoting they reported on a maximum of 40 Tons (88,000 PSI! assuming they used Metric Tons) for BP and had 'heard of' 60 Tons (132,000 PSI) for Nitro. This was in a fully filled and tightly closed vessesl. Probably for Blasting tests or Military Cannons. (Do not try this at home! Pressures may not be the same pressures as in newer test equipment.)

There wasn't any pressure data in the Barrel Brusting tests (they were probably having way too much fun blowing things up). I expect pressures were no where near 88,000 PSI. The barrel walls would have to be at least as thick as the bore is wide to hold that pressure.


Last edited by Bob S on Thu Aug 11, 2011 8:03 pm, edited 3 times in total.

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 Post subject: Re: Black or Nitro Powders for Damascus?
PostPosted: Sat Jun 04, 2011 7:23 pm 
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Joined: Wed Jan 12, 2011 9:55 pm
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OldSkeeter:

I remember you; you're the guy that insulted my intelligence in your first reply. Classy!




Last edited by Bob S on Fri Jul 19, 2013 8:07 pm, edited 2 times in total.

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