doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Damascus Pits

When I purchasedmy old English Damascus hammer gun, it was afflicted with one "medium" internal pit and two or three pinholes in the right barrel. The left barrel was flawless. I had Mr. Merrington inspect it and he deemed it sound. Next, I subjected it to 100 x RST 3/4 oz 2 1/2 ultralight 7 1/2's, 4800psi at clays. No additional pits. Next, it digested 100 x 7/8 RST lite loads #6 5400psi in a driven hunt and 30 x 1 1/16 oz #5's in a preserve hunt (same day) 6900psi. Following that outing, am now up to 8 pinholes in the right and 4 in the left where there were none previously, at least to my untrained eye. Are additional pits inevitable with these old guns, or is it possible that have I abused these barrels with the shooting described above, resulting in additional pitting?

Some of them English chaps think they can measure pits
...I'm sure what Merrington did was deem it safe to shoot....but that's walking way out on a limb with any vintage gun.

I've owned and shot several Damascus barreled guns without any problems...but the truth is no one should be shooting any of the 100 yr old guns for a variety of reasons especially one with any kind of issues.

Ps...I'm sure one of my bOys will be along shortly to argue different

That is a rather sweeping generality. It�s also one many here would disagree with. Care to name any of the reasons that you suggest apply to all shotguns that are 100 years old?

They're old...

Stick a fire cracker up yer old arse and see how long you last.

All but the best guns barrels were hammered by chraftsman of varying skill levels in all kinds of eviroments.

Care to tell why you think 100 year old damascus is safe to shoot ?

Not much doubt his gun will most likely never explode on him.....God only knows for sure and he ain't talking.

I agree. Joe should never shoot a 100 year old damascus gun. End of discussion.

As to the OP, shooting the gun likely pulled every minute trace of oil out of the barrels, making more of the small pitting evident. It was always there. Freshly oiled bores will often mask fine pitting, making it hard to detect unless it is VERY thoroughly cleaned out with alcohol (or shooting).

Agree completely with Cannvasback and what Flintfan later notes.

The pits were probably there the whole time and unseen.

While there is always a level of risk in shooting old guns, that risk is small to non existent when properly inspecting and feeding the correct pressure ammunition.

Other than by honing it is improbable to find an old gun completely free of pits. Yes they are out there, but virtually unseen by most of us

If Merrington says they're ok, they're ok. Your loads were very conservative. When you say pinholes, do you just mean small pits? Not true holes?

If we all stopped shooting anything with pitting it would take a lot of guns out of use. I think Flintfan is correct. Shooting may have made them more visible.

I do have one set of pitted barrels that I won't shoot. A set of Greener barrels that are perfect on the outside and heavily pitted inside. I temporarily modified my wall thickness gauge by gluing a conical brass point onto the "ball" that goes into the barrels. This went into the pits and I got readings of 16 thousands in many places. And I realized the pitting might be even deeper. Fortunately the gun has a second set of barrels that are fine.

And who's really sure if the pit was caused by corosion or a flaw in the original construction that took years to surface ?

The old guns are cool to shoot...Damascus was the best technology of the day I've shot my share but moved on

Yes as far as the description of the pits, they are so tiny they look like pin pricks. No true holes. Come to think of it, they did become more noticeable after I gave them my end of season wire brush-out with Hoppe's #9. There very well could have been there all along with some oil obscuring them. I am pretty confident the gun has not been shot 300 times since its 1974 reproof.

I am cleaning them as I would steel barrels. Are there any special cleaning measures or precautions I should employ for Damascus?

The sage of the sOuth is correct that it is impossible to know the wall thickness, or evidence of active corrosion, at the bottom of pits. The wall thickness gauge pin can not reach the bottom, and obviously the medial barrel surface of a double gun barrel can not be evaluated.

We do however have excellent tools to see every mm of our barrels.
The Hawkeye� Pro Hardy Direct Borescope would be the $1500 or so standard.
http://www.gradientlens.com/Rigid-Borescopes/Hawkeye-Pro-Hardy.aspx#6861-overview

Lyman sells a rigid digital scope
https://www.amazon.com/Lyman-Products-Borecam-Digital-Borescope/dp/B00URUE84W

And there are flexible digital scopes for $13 to $130

This one is $38 and highly rated
https://www.amazon.com/Endoscope-Depstec...R1VCH5FEAX7YM71

Really no gOOd excuse for not knowing the condition of our vintage barrel bores

re: cleaning I would avoid the stainless steel Tornado brush; they are available in brass
https://www.amazon.com/Pro-Shot-12-Gauge...BRN5HZE89BMD9JR

And on the subject of pits and NDT.
The advantage of radiography is that is might show a defect within the barrel wall, invisible on inspection. The problem is that magnified spot images also show pits (the lucent areas) and it can't be know definitively if the defect is ON the barrel wall or IN the barrel wall.
MPI would be negative if there was no microscopic defect/crack to the surface.

Owen, seems no one is addressing you original question. No, there is nothing you could have done to create pitting in a short time. You just uncovered it. Generally, light to moderate pitting has no influence on the safety of the gun, assuming proper ammunition is being used.

I shoot a number of damascus guns and don't vary their cleaning from fluid steel barreled ones. I will say a favorite cleaning tool of mine has become a bronze bristle brush wrapped with part of a Big 45 Frontier Metal Cleaner pad and spun with a drill back and forth through the bore. Does an incredible job of quickly removing lead or plastic.

Joe, Thanks for the cleaning insights. I have precisely the arrangement you describe with the Metal Cleaner pad and bronze bristle for spinning in a drill (picked up the idea from this Forum) for use in steel barrels, but was hesitant to use it in the Damascus barrels. Hopefully there is no downside to spinning it in Damascus.

Sorry for the obtuseness and I'll try again.

Proper evaluation of vintage barrels (steel or Damascus) require direct visualization of the bore. I agree the pits were present on purchase and would have been seen with a bore scope.

"Light to moderate pitting" in the chamber or just past the forcing cones is a different issue than pits in the distal 1/3 of the barrel

Typical superficial pits just past the forcing cone



These erosions would be of concern



Can't know if someone doesn't look, using the proper equipment.


Owen: composition analysis of pattern welded barrels show them to be wrought iron and low carbon, low alloy "mild" steel with a Brinell Hardness level of about 100; much softer than stainless steel and even a bit less than Phosphor Bronze
http://www.aertesting.com/uploads/3/3/5/8/3358290/bhn_of_various_materials.pdf

Hoppe's 9 has a Phosphor bronze brush.

I'd stick with copper and the Big 45 product. It is reported to be "a proprietary alloy containing stainless steel, nickel silver, monel (a corrosion resistant nickel based alloy), and zinc" but is likely mostly (soft) zinc.

Besides not being able to spell and barely being able to express a coherent thought, you still haven't backed up your original assertion with any kind of reasoning. So, to confirm things....according to you, the mere fact of being 100 years old means a gun is inherently unsafe and should not be used.

Better send me one of those useless Scott Premiers that may be hiding in your safe. Useless old things taking up space that might be better utilized storing a nice semi-auto with a scope on it.

Dr. Drew, My pits are much smaller and less numerous than the two photos depict. The barrels are mirror smooth up to the 1" area with pits. However, they are in about the middle of the barrel, a poor location. I understand the scope is the best way to see them and evaluate depth. I think I will grab one of those scopes and have a look...

Great idea Owen, and please post images, and the inches from the breech, in follow-up!
or send full size jpg attachments to revdoc2@cox.net

I believe David Williamson has images obtained with the inexpensive digital camera which he might be kind enough to post.

Interesting subject here. I've reversed my personal opinion on Damascus barrels & pitting several times during my period(s) of ownership and use of them. As much as I truly love them (as the "art" they very-much are), I'd be deeply disturbed if my use resulted in so-many additional "pinholes" in such short-order. I'm not sure I could continue to use such a firearm w/o considerable distress on my part.

I once asked one of the most knowledgeable gunsmiths in the south about looking in the barrel of a Damascus barrel gun with a bOre scope....his reply was that if I did I'd most likely never shoot it again.

The gun in question appeared to have pristine bores to the naked eye.

What happened to the Teague lining system? I've not seen an ad in quite awhile. It looked like a good idea on the surface.

Barrel lining is no longer offered by Teague. Word was that the bonding agent used was not reliable
http://www.vintageguns.co.uk/articles/barrel-lining

And word has it that they went through a couple of barrel's walls in the boring process thereby ruining the barrels.

There is no way that simply shooting Damascus (or any other barrel material) would cause pitting or pinholes such as those being discussed here.

Whats the name for the bad spots in Damascus ?

Well, it looked like a good idea. Thanks for the link to the article Dr.

jOe...??

Occlusions.

Isn't there another term for occlusions caused during the construction/forging process ?

"Inclusions" maybe to include slag or scale?...Geo

INclusiOn



and "Sand Holes"
Shooting: Its Appliances; Practice; and Purpose, James Dalziel Dougall, 1875
http://books.google.com/books?id=-ToCAAAAQAAJ&pg=PA25&dq
The �sand-hole� is a thorough flaw; and if the barrel stand the proof at all when it exists of any size, still it cannot be quite safe, as the hole will often run in a tortuous direction for a considerable length under the surface, being, as its name imports, full of fine sand, or probably of the powder used as a flux to promote complete adhesion in welding the barrel, which has adhered to the iron, and been closed upon in the act of forging.



That's why "rough forged tubes" are proved.

And the idea that (properly fabricated) pattern welded barrels deteriorate over time related to internal corrosion/rusting has been proved to be totally bogus
https://docs.google.com/document/d/1ZnptAPvQIlWG5n5UU2FmKcFpYtVmOSc4b7K7G9IBs4g/edit

BTW: Remington paid a lot of $ (mostly to the class action lawyers) over manganese sulfide "stringers" in AISI 1140 Modified barrels.
Loitz vs. Remington Arms, 1990
http://law.justia.com/cases/illinois/supreme-court/1990/68367-7.html

As did Savage recently related to the Savage 10ML II (designed for use with Smokeless Powder) with Crucible 416R Chromium Stainless Steel barrels. It is alleged that catastrophic barrel failures have been the result of both a design flaw and a metallurgical flaw; manganese sulfide inclusions in the 416R
https://cases.justia.com/federal/appellate-courts/ca6/12-1475/12-1475-2013-08-09.pdf?ts=1411028258

The big $s are in oil pipeline blow-outs and planes falling from the sky, and the NDT industry and Forensic Metallurgists are pretty good at figuring out why.



http://www.wsj.com/articles/southwest-incident-linked-to-cracked-engine-blade-1473716012
Fan blade was shown to have a crack by MPI and not replaced during maintenance

Dangerous world out there and just another reason why none of us need guns...or cars...or planes

Putin?

As I recall the G grade Parker which which was "Blown Up" at about 30K PSI was badly pitted throughout the bores. The pitting was apparently not what caused it to burst, but the pressure had simply exceeded its limit. It blew between the chamber & the hole for the extractor leg, as did a similar steel barreled one at near identical pressure.

Buck Hamlin also tested both an L C Smith & Lefever (forget the grades) with badly pitted bores. Both were rechambered for 3�" shells. He began with the heaviest reload listed by Alliant using Blue Dot powder behind 2 oz of shot & went up from there. He stopped on the Smith when the gun would no longer stay bolted when shot, that rotary bolt became a "Self Opener".

He went even further with the Lefever (its simple wedge bolt in the Doll's Head stayed bolted) until he produced a bulge out where the walls had been thinned by the extended chamber. Realize of course this was a 3/4" chamber extension, not the usual �" from a 2� to a 2 3/4" chamber.

Those old Damascus barrels are just not as weak as we have been told. Most of them which have burst over the years,, "When" a proper investigation was done has been revealed were burst for some other reason than that they were made of Damascus Steel. A lot of early mis-understanding of Smokeless Powders resulted in a good number of burst barrels. Twist & Damascus barrels were high on the list for the simple reason they were the barrels in common use at that point. When these same Overloads of smokeless (from using a bulk dipper with Dense powders) were used in steel barrels they also Blew Up. The most common cause was, & still is, Barrel Obstructions.

Sherman Bell's destructive testing is referenced toward the bottom here. Any library can request back issues of DGJ
https://docs.google.com/document/d/1LFnSG34k3mBhLEjEgU267wAlIa215MNVQZhIiY62Hx4/edit

Buck Hamlin�s Lefever destructive testing, courtesy of Tom Archer
http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=422672&page=2
Buck Hamlin was given an extremely well-used damascus barrel Lefever with a burst right barrel just past the forend tip. The barrel wall thickness at the rupture point was .010�, and the chamber was 2 5/8�.
With the intent to rupture the left barrel, Buck measured the bore diameter and started his effort with a box of 2 3/4� 1 5/8 oz. short magnums. After 25 shells the left barrel had no change in bore diameter. He then lengthened the chamber to 3�, and following 25 1 7/8 oz. magnums (lead #2 and BB) there was still no change in bore diameter.
Buck then lengthened the chamber to 3 1/2� and used 3 1/2� 2 1/4 oz. lead turkey loads. The left barrel blew after only a few shots. The wall thickness at the rupture point, which was almost aligned with the bursting point of the right side tube, also measured .010�.

jOe's results might be different

Common sense should tell you a 100 year old barrel forged with no quality control has long past it's prime.

Why let evidence and facts get in the way of firmly held emotional beliefs.

More and more jOe, you provide evidence that you are a lefty. Living' in a world ruled by your emotional reaction to people and events rather than the facts, reason and logic.

That's okay though. Maybe one day you'll get all emotional about something I say and send me a nice Scott Premier.

The study group is too large for what little evidence or fact that's offered to mean anything.



Ps....I sold my Premier.

Damn!

Joe...wasthe word Grays or Greys?
franc

Either one Franc

Shooting Simplified, James Dalziel Dougall, 1865
There are various kinds of flaws in barrels�what are technically termed �grays.� They are those little specks in the iron�from rust showing more upon them than upon the smoother surface.

The Gun, W.W. Greener 8th Edition, 1907
The numerous twistings and weldings of gun-iron rods and ribands are fully detailed�and it must have occurred to the reader that the Damascus barrel is one mass of welds from breech to muzzle. This is so. Unfortunately a certain amount of burnt metal, or scale, is imbedded within some of the welds, and in the finished barrel this fragment of scale forms a �grey��which will not colour in harmony with the other part of the barrel, but is made more apparent by the finishing processes of polishing and browning. These �greys� may appear some time after the gun has been in use, the hard metal composing the barrel being eaten into by rust�They are developed in the inside by the chemical action of powder gases, and are almost ineradicable. The harder the Damascus the greater the liability to �greys��

They are a cosmetic flaw, but not felt to be a safety issue

And greys don't turn into pits on the inside of the barrel ?


A pit is liken to a cavity in your tooth that can't be fixed. A pits growth might be slowed down with oils but can never be stopped from growing.

Dr.jOe

I took a chance on a Clearview Engineering Borescope for a gun show tool. Simple, cheap and surprisingly gives excellent clarity. I still have normal near vision and the instructions suggest trying the scope with and without glasses if needing readers.
For me, the focal point is only about 2" from the end of the 8" tube, but that would still allow detailed examination of the chamber/cone/about 7" of proximal barrel and 10" at the muzzle. Obviously it moves freely in a 12g barrel and you can almost get a 3-D sense of the pits
https://4570products.info/Clearview-Brass-Bore-Scope-16.htm