doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Damascus barrels and pressures

I do find it interesting how much modern steel barrel quality has apparently improved. I recently bought a 28" 12ga Charles Daly 512 st sxs to use strictly as a target gun, and found when it arrived that it only weighs 6lbs even, with thinly struck barrels, and yet it has 3" chambers. I can't even imagine touching off a 3" round in such a light gun. I'm worried enough about recoil even using normal 2.75" target loads in it (I will be shooting it for the first time this weekend).

By comparison, my 1890's damascus Lefever 12 with 30" barrels, and 2 5/8" chambers, weighs 6.5lbs, with similar thinly struck barrels. I have no qualms shooting 2.5" RST's or equivalent reloads in it, which is how it was designed, and I have hammered roosters out to 50 yds with those loads in that gun, and I intend to do so for many more years.

I used to worry about this stuff, but decided if my barrels (Damascus or other wise) met spec and were not pitted, that I could safely shoot them with both handloads and commercial ammo...

I shoot my only Damascus barreld gun (1897 Linder Daly 20 G) with standard Winchester AA 7/8 oz, cartridges. The barrels are MWT of 30 thousandths.

Ha ha thats the first thing I thought when I saw that name, the George the Animal Steele!

keith,

I too thought of "The Animal" immediately. I remember him with his GREEN tongue and a ton of hair on his back!

MarkLarson,

Did you mis-type the weight on your Lefever 12-er? That's incredible! My daintiest (which is also an early gun) weighs in at 7.25. My heaviest 12 is a late gun, weighing 8 lbs 2 oz, with THICK flag Damascus barrels. Buck Hamlin's comment was, "I don't care if you shoot turkey loads through these!"

- Nudge

Nudge;
I too have a Lefever 12 which weighs 6� lbs. Mine is to date I believe the highest numbered one we have recorded, unless another has come to light which I am unaware of. It has two numbers only 4 digits apart; 73,338 & 73,342 as I recall. It would be from the Ithaca era & is an H grade with
"Best London Twist" barrels. Is fitted with an Infallible SST, probably original to the gun, but is a non-ejector. The rest of my 12 gauge Lefevers weigh from just over 7 lbs up to 8 lbs.

Miller

I recall your discussing this gun on the old Lefever forum...but didnt know it is so light. Have you ever compared measurments with your others? Across the water table, between the firing pins?

Nudge

Yes, but off hand I don't recall what the firing pin spacing is. The measurement across the water table is virtually the same as an 8 lb G. I have heard of some 12 gauges built on the XX frame but this one was not.

On my 16 gauge on the XX frame the bar is both narrower & shallower than non XX frame.

My experience is that heavier Lefevers have a wider & taller breech with corresponding thicker walls around the chambers & a wider firing pin spacing.

Some time back in a discussion on this I measured all of mine & posted the dimensions. They are I suppose still somewhere on the forums here, but I'm not very good with the searching aspect of the board.

Nudge, the very first Lefever I bought is a 12 ga. FE that weighs only 6lbs. 3oz. on an accurate scale. I also have a 12 ga. I grade which is only a couple ounces heavier. But most 12 ga. Lefever guns I've weighed have ranged between 7 and 8 lbs.

About a year ago, I made a post here that detailed a bunch of weights and frame dimensions of a number of different Lefevers across a broad range of serial numbers. Here's a link to that thread concerning Lefever frame sizes:

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=506188&page=1

The small frame 12 gauge guns are a delight if you can find one, but I've only ran across a very few. I still haven't seen a 12 ga. Lefever that has the xx stamp on the frame as found on 20 and 16 ga. guns, but some people claim they exist.

You are absolutely correct; fluid steel can also be damaged by excessive pressure. The tensile strength of fluid steel, for a given barrel thickness, and assuming modern alloys, has two advantages: raw tensile strength and homogeneity. Damascus steel yield strength is typically in the 7-800 megapascal range; modern steels go up into the 2,000 megapascal range, but could also be low, in the 500 MPa range for a plain carbon steel. Damascus steel is heterogeneous, by the nature of its construction from layers of dissimilar alloys. It is the dissimilar alloys, however, that engender the problem; I had a long discussion with an electrochemist about galvanic interaction at grain boundaries and micro-corrosion at the boundaries of the different steels, which weakens and changes the tensile strength of the material over time, when I bought my Barlow, in an attempt to determine the safety of firing it. In addition, hydrogen embrittlement, which can happen with all steels (hydrogen is a small molecule that can diffuse into steel at atmospheric pressure) takes place the more so in Damascus steel because of the presence of a greater number of microscopic voids and incompletely fused interstitial surfaces. Both electrochemical processes can give rise to internal stresses in the metal, which themselves spontaneously change its yield strength over time. Finally, there is no such thing as "Damascus steel" - Damascus is a process, not a material. It is not standardized, in the sense that the number and particular alloys of steel used, the forging temperatures, and the process can all vary from barrel to barrel, as well as between manufacturers. It's like saying that cats are nice; they don't all come from the same mold, and saying a tabby is affectionate has no bearing on the behavior of a leopard.

When Damascus steel is used in the creation of a black powder gun, with insight and testing, the thickness of the breech end of the barrel is designed, as I said above, for the stress profile of a black powder round. Peak pressure in a black powder round generally happens between 125 and 200 microseconds after ignition start; peak pressure in a smokeless round at around 250 to 400 microseconds, although it is highly dependent on the powder used, which is indeterminate a priori. That doesn't sound like much of a difference, but when you are accelerating the shot payload at about 3 to 5,000 G, the distance it moves in that time is significant. That means that the peak pressure may, or may not, move down the barrel away from the breech. If the barrel profile was not designed for that, necessarily it would be subject to strain - that is, exceeding the ability of the material to elastically return to shape. In a hybrid alloy, where internal discontinuities occur, that in and of itself can initiate failure. The difference with a fluid steel barrel is that in order for that to happen, you have to have an overpressure condition relative to its design strength; with Damascus barrels designed for the firing of black powder cartridges, you don't need an overpressure condition; you only need the pressure to be in a different area of the barrel from that for which the barrel was designed, which by definition can be the case for a black powder weapon firing a smokeless reload.

Obviously, if the Damascus barrel was designed and built yesterday, and specifically for smokeless powder cartridges, the above does not apply, since it would exhibit the excellent properties of high yield strength and elasticity inherent in steel made by the Damascus process. But a barrel made 150 years ago, of questionable provenance, fired with black powder loads and subject to uncertain cleaning and a century of salt and galvanic corrosion and micro-structure Hydrogen infiltration is one that deserves closer inspection than "Oh, them old Damascus barrels could shore take it." What motivated my comment was that in reading the posts, it sounded like posters believed that there was some "mystique" about Damascus technique that made it invulnerable to failure, which I felt was bad advice and a bad rule of thumb. As old as my hands might be, I like both of them just the way, and in just the place, that they are. So I posted a cautionary word to counterbalance the impression I got, out of a sense of responsibility. To your left hands.

As for the other good-natured cracks: no, I haven't visited this forum before under another assumed name. I share a number of commonalities with "George the Animal Steele;" like him, I have a bachelor's and master's degree, but not from Michigan, like him I was a track and field and football athlete, but it was my father who was a wrestler, not I. I have been nicknamed "the animal" (when I played football as an offensive guard and defensive end, because I broke so much of my equipment, including my helmet - which may explain a lot about my occasional incoherence), as well as Rusty, Stainless, and Remington. But I sure don't look like him. Sorry if my attempt to share advice I received in good faith from a scientist ruffled the feathers of the old-timers here. Peace.

First let me say I am not a Wrestling Fan & George Steele was not a name I recognized, sorry about that. I have therefore made no disparaging remarks as to your name.
I do however see a few Flies in the Ointment though concerning some of your statements. First powders from around the range of Unique & faster reach their peak pressure Closer to the breech than does Black. Secondly most doubles built from around the 1890's onward whether in steel Damascus or twist had their chamber walls thicker than some earlier guns with the knowledge they were apt to be used with smokeless. In shoe rt They were designed for smokeless & they stated so.

As to this deterioration from Galvanic Action this is quite possibly theoretically so, in Practice however it just doesn't appear to be occurring.
In Practice it is actually much easier to find accounts of failures in early steel barrels due to material flaws than for the welded barrels. A void in the billet when drawn into a tube would leave a seam, many were caught in proof or finishing, but not all. The forging process on the welded barrels eliminated these voids. There was of course always the possibility of slag being trapped, referred to as Grey's in the welded barrels. In reality these were more cosmetically unattractive than actually dangerous.These were not drawn put into seams but at worst were no more than the vent hole in a flintlock.