I recieved my Skeet Shooting Review today and in the mag Tom Roster had a major article on why not to shoot damascus and how much he enjoyed testifying in court about them being unsafe. He also took several shots at all the thinking that was wrong. In case anyone wants to contact him the "expert" provided his email address. tomroster@charter.net

bill

since a lot of us most likely don't get the magazine

what was his reasoning?

and did he mention that the British proof houses will nitro proof damascus in proper condition?

Roster knows a lot about a lot of stuff. But it's unfortunate he writes for Shooting Sportsman--a magazine read by quite a few people who shoot Damascus guns. He comes up short in a lot of areas where proof, pressure etc are concerned.

He needs to spend more time talking to Vic Venters, who's done some good articles (and chapters in his book "Gun Craft") based on spending time at the Birmingham Proofhouse, talking to current and former proofmasters, etc.

That being said, Damascus guns ARE potentially unsafe . . . if you shoot the wrong ammunition in them. But then so are a whole lot of vintage fluid steel-barreled guns.

Billy Franklin’s expanded version of Vladimir Lenin’s statement
“If a lie is repeated often enough all the dumb jackasses in the world not only get to believe it, they even swear by it.”

Damascus Mythology and Reality
https://docs.google.com/document/d/1LFnSG34k3mBhLEjEgU267wAlIa215MNVQZhIiY62Hx4/edit

Very frustrating to see Roster's article - disappointing really. Just as it seemed some progress was being made in the "damascus = always bad" mythology.

Wonder what his "expert" consulting services cost?

Frankly I'm happy to see damascus barrels receive bad press by esteemed "authorities". The market for them is already way too high and as a public service I have been trying to take all of them off the market.......and into my collection.

I wonder if there is any way to get the article published in more widely read publications.....

Hell, anything is "unsafe" if it's pushed beyond its limits. the worst accidents I've ever seen with guns all had modern fluid steel barrels.

I'm going to maintain that damascus barreled guns in the hands of knowledgable shooters are safer than most any modern made gun. Rationale: we are acutely aware of the limits they have from their age and construction and treat them accordingly without playing roulette. The insanity I see reloaders casually embrace every week with modern guns is what really frightens me.

Amen.

SRH

I guess Roster, along with everybody else in the world, is entitled to his own opinion. But to state your opinion as 'fact' is as wrong as your (Mr. Roster) flawed opinion - which must be based on rumor and conjecture, as he has probably not had any personal experience with a Damascus gun's barrels failing when he was shooting.

Mr. Roster, your opinion, in the case of Damascus barrels being collectively unsafe to shoot, is pure sheep-dip.

Someone snap some photos of the article and post them here. I wanna see it.....I need a good laugh.

Much depends on type and country of origin. For example, I read in very reputable reference that three strip Birmingham trade stuff was second only to Sir Joseph Whitworth Fluid Compressed Steel at the time both were offered. Anyhow I would not worry his faux assertions will keep prices down so we can all enjoy those guns at lower prices. I noticed that British guns with damascus barrels list for considerably less than those with fluid steel barrels. Let us keep it that way.

Well if he is talking about shooting Wally World type modern factory shells he is right they are not safe to shoot. If he is talking about worn out guns with heavily pitted barrels or barrels honed so thin that they are paper thin the he is right again. If he is talking about shooting reloads in them of such poor quality, that most Skeet shooters seem to shoot on a regular basis, then he is most like right again.

Now if he is talking about guns with no pits, not honed to death, using the proper type and pressure level loads in barrels that have been inspected by a competent gunsmith then he is wrong. I was very timid when I started shooting Damascus barrels about 20K ago. Now I just use the right shells win guns in proper conditions and enjoy the heck out of them.

Blanket statements are used by experts and fools. The difference, if their is one, is that experts want to be paid for their opinions, even when they are wrong, fools give us their expert opinions for free right or wrong.

I take his reasons and opinions with a large grain of salt. Safe is safe and it is up to the operator to make sure things are as safes as possible. I hope his expert opinions do decrease the prices of a couple of guns that I am looking at. Maybe if I forward the article the seller will cut his prices in half.

I hear it at Gun shows all the time when the common Hunter walks by looking at a table full of vintage sporting arms and they make a comment about Damascus barrels being unsafe to shoot. Or they explain to their kids how they can't shoot guns like that.

I don't even interject anymore. I just allow the ignorance to amuse me.

Those are the same type of people who think it os the coolest thing to pull both triggers at the same time when shooting a double. And then post a video on YouTube about it.

What is an EXPERT ? Seems to me those with a great deal of knowledge never define themselves as expert. The term "expert witness" always seemed an oxymoron!
Best,
Craig.

and Praise the Lord!

A lot of ignorance out there as it pertains to damascus barrel guns. Too bad someone like Roster who has a forum to talk from adds to the ignorance.

I agree with the earlier poster who said he wished Roster did not write for SSM. I could do without his articles too. In SSM it seems he has an agenda on the steel shot issue.

We know that many people for years loaded their own cartridges for personal use in a small and large capacity using black powder.

The reasoning for the early reports of issues of damasc and nitro are as follows.

Lack of education/fundamental understanding of the differences between blackpowder and smokeless, leading to seriously overloaded cartridges, the scoops and measures for black throw large volumes of powder, average joe using the tools he has reloaded with for years gets new fangled smokeless to try without understanding the differences the volume load his measures throw would obviously be overloaded.

Thin barreled guns, like the early CF guns that were converted from percussion or muzzle loading guns with very thin svelte barrels to start with, and often no radius to the action rarely pass nitro proof now and obviously did not back then.

( if you want proof that these early CF guns fail NP look at the June Holts sale catalogue in stocks actions and forends and you will see several of those i describe )

Damascus type steel probably doesn't even need to be mentioned, but apparently it'll come up in court. Maybe a little caution is wise when shooting any hundred something year old gun, particularly the safe mono steel ones. I also wonder if the proof process has anything at all to do with the decisions that shooters make.

I'd wonder if other experts might join in and start calling for proof of damascus barreled guns in the US just to 'settle' the issue. Thank you Demonwolf and your fellow countrymen for commenting about the realities of proof when you brought up trying to get your Trantor patent gun back in proof. That gun will still need a responsible shooter to operate it.

I haven't followed the skeet game for a while, but I wonder if it was a thin issue that needed filler.

There are so many variables when it comes to old guns.

I do not put iron faith in proof i have two out of proof guns on ticket, an antique and the tranter patent, i have shot many more, but i fully support it at point of sale as you really can't assume the person buying has the same knowledge or understanding you have. And even then the best informed of us using our best judgement realize we are not infallible i strongly believe that individuals using these old guns understand this.

Antique guns in the collectors market in the uk are bought and sold as antiques, but if an individual wishes to enter an antique onto their certificate its assuming that if they are doing so they also have the knowledge to use it safely, many of these antiques are out of knowingly out of proof and many of them end up being entered on to certificates and legally shot.

Its not illegal to own and use an out of proof gun, just illegal to sell it.

The Lang tranters patent still poses an issue for me, i have shot it and shot reasonably well with it on some wood pigeon with black powder loads. Part of me wants to leave it out of proof and enjoy the gun. Part of me want to BP proof it just so it can be sold if i ever might need to. Part of me wants to nitro proof it, so it can be a real usable piece today and of interest mechanically.

If i do re proof in any way i will keep a record and picture the whole process of prep right through to the proof house where i will probably take it in person, if i decide to proof, i think if i do it this way even if it fails we all could learn something from it. - and then the next project can be making some new barrels!

Over the years, I have testified in 35 different court cases at the federal or state level, throughout the country in the field of firearms and ammunition.

The court generally qualifies you as an "expert witness" in a given field or specialty. Personally, I never liked the term. I always felt (and still do) that a true expert does not know everything. A true expert knows where to go to get the correct answer.

Each court is different, as is the judge presiding over the case. Some judges will instruct the jury that even though you are testifying as an "expert witness," he or she is merely offering an opinion.

I have personally witnessed well respected "firearms experts" testify incorrectly in open court. Some even acknowledge that they were wrong during rebuttal. I never wanted to be that person. I always did my research, checked various sources (not just one), and used original factory data if at all possible.

Someone's freedom is on the line here , and you had better be right. The defendant may very well be a real bad guy, but he deserves a fair and honest trial. That's the way I always approach it anyway.

A little off-track to the subject matter, but Craig mentioned what is an "expert" so I chimed in.

Interesting he said he has testified in court cases on Damascus guns. That would have records available.

If there have been recent court cases on Damascus guns failing I have never heard about them. Not to say it's impossible just you would think they were reported. Who would somebody sue, maker long out of business ?

Could it be another reporter caught fabricating facts ?

Boats

Sheep Dip is pretty good scotch. And remained available under that name purchased from the vet. no less, when they went the wrong way across the pond as we did w/prohibition, making the common and uncommon man both suffer that sufferance. Common sense finally prevailed, but Sheep Dip kept its name.

The Damascus vs. fluid steel thing has been around since the very introduction of fluid steel bbl's. Can you imagine that!? Some Damascus patterns could make good wood blush. I wish that we had a compilation of Oscar's writings on the subject accompanied by true colour plates. A finely bbl'd Damascus gun is precious ... in the Gollum sense. Think Purdey doesn't know that!?

I assume this is the same Tom Roster who is an anti-lead shot disciple and who often tries to tell us that steel is the ballistic equal of lead shot. Even better in some respects according to him, because of better pattern percentages from the same choke. But he neglects to tell you that the steel shot with its' better pattern percentage contains significantly less shot per ounce because of its' lesser density or specific gravity.

Needless to say, I am not impressed with Tom Roster's firearms knowledge. Just wish I hadn't spent so much of my life believing people like him when it comes to Damascus.

i couldn't agree more!

Could be going after ammo makers . . . although US shotshells usually carry the warning that they're not to be used in Damascus guns.

Concerning Roster and steel vs lead: To give him his due, I don't believe I've ever read him claiming that steel is better than lead. Or even as good. He has done a lot to demonstrate that steel is better than many naysayers would have us believe. At the same time, his research involving steel and pheasants (which probably needs to be updated--he used pretty anemic steel loads) revealed some issues that he hadn't observed with waterfowl.

He is convinced that lead shot is probably going to be prohibited in the near future. I think he's wrong about that, given the current political climate and the likely linkage of any lead ban to an assault on gun rights in general. But he simply doesn't have the expertise in the field of vintage guns, proof, pressure etc that he does when it comes to steel and other varieties of nontoxic shot.

I have only been shooting Damascus for about 30 years, so I am no expert . I am in the Securities business and I find that the Annuity bashers seem to be supported by the Mutual Fund companies and vice versa with the Mutual Fund bashers. Since Tom
Is generally supported by the modern gun and shotshell manufacturers, it gives me the same thoughts of conflict.

Larry,
In CA, we've been legislated to going lead free on all hunting by 2019, I believe. That pretty much kaboshes my .410 quail/chukar hunting here. It wasn't great hunting in CA, but it had its moments.


I have some 20ga BSS guns that I can use for steel if I need to hunt here. Otherwise, I'll spend more time (and money) in neighboring states that allow lead.

Never have thought much of Mr. Roster's writings or stances on lead shot. His articles in Sporting Clays magazine, which comes with NSCA mebership and is the same crap over and over, are not worth reading.
JR

Again. Has anyone seen the article he wrote in that skeet magazine? Let's not hang him till we have seen the evidence.....then it'll be ok to string him up. Let's see some direct quotes. I agree on what I've seen in SSM, it's generally not worth wasting time on.

I recently read a comment by him in a question and answer section in a gun magazine where he said Damascus shotguns were unsafe to shoot. I emailed him saying the British proof house still proofs Damascus barrel guns for nitro, and if they're so unsafe, why would they still pass them. Also mentioned Sherman Bells testing in DGJ and all he said in his reply was " as long as American shotgun shell manufactures say they're unsafe, I'm sticking with them". Maybe that's what qualifies him as an expert.

Hi all,

I'm a long time double owner, but new contributor to this forum. I think most of us with experience shooting Damascus know better...but for those who are still unsure, or who are prone to parrot wives tales, I would point to Sherman Bell's excellent series of articles in the Doublegun Journal entitled "Finding Out For Myself."

Using a bunch of rather junky old donated barrels, including fluid steel, Damascus, and twist...the testing was done by Tom Armbrust of Ballistic Research in Illinois. Larry Potterfield of MidwayUSA donated a large share of the barrels.

Basically, using insane proof loads they could barely damage any barrels with crazy PROOF loads! Tom told me the only way they were able to really damage the barrels was by obstructing them...leaving a jag in there...jamming a 16 ga shell in front of a 12ga...that kind of thing.

By the time they were able to get failures...the loads were RIDICULOUS, and as I recall the fluid steel barrels actually averaged slightly WORSE than the Damascus.

My personal belief is that when the world moved from black powder to smokeless, no one explained well enough to the public that the measurements were NOT one-to-one. So it took only a few people to load shells with smokeless in place of black powder using the same recipe, and ka-BLOOEY. Because the black powder/smokeless transition happened around the same time fluid steel was getting popular, I think people concluded the reason fluid was coming out more was because it was proven stronger...or that you NEEDED fluid steel for smokeless shells. Then it took no time for word to get around that Damascus barrels were weak. Just my opinion.

I want to stress that the barrels Tom tested with were, according to him, absolute JUNK. And they still held up. So consider how much better put together your gorgeous American Flag Damascus barrels on your high grade Lefever are!

The "Finding Out For Myself" series Sherman Bell wrote were done so over a bunch of DGJ issues...I'm sure they could be back-ordered. I know of no one else the, or since, who have put that degree of unbiased time and energy into actually testing Damascus strength the way Sherman and Tom did.

- Nudge

Chuck--I feel for you Californians. Unfortunately, hunters and shooters in CA are not a large enough minority to make the noise they would need to make to fend off the anti-lead movement. I'm sure it will happen other places too. But fortunately, not many places where there's really good upland hunting, because those places tend to have a far higher % of hunters than CA. Thus more likely to get the politicians' attention. Moves to expand nontox requirements have been shot down in MT, WI, IA, and SD. Maybe other places I'm unaware of. But we need to remain vigilant, because the anti-lead "environmentalists" will keep trying.

Welcome Nudge, and here you go:

The Double Gun & Single Shot Journal "Finding Out For Myself" series by Sherman Bell with technical assistance from Tom Armbrust
Vol 10, Issue 2, Summer 1999, Part 1, p. 9
Vol 10, Issue 4, Winter 1999, p. 21 - Destructive testing of Parker GH Damascus
Vol 16, Issue 2, Summer 2005 - Destructive testing of Parker VH Vulcan Steel
Vol 17, Issue 3, Autumn 2006, p. 12 - Destructive testing 8 Damascus doubles
Vol 17, Issue 4, Winter 2006, p. 28 - Destructive testing 7 Damascus
Vol 18, Issue 1, Spring 2007 -
1. Destructive testing on a Damascus barrel with thinned walls; calculated by O.D. - I.D., not measured
2. Destructive testing using various obstructions, including a 20g shell
3. Destructive testing using a shell loaded with 3 1/4 Drams by volume or 56 grains of Unique (similar to “Infallible”) with 1 1/4 oz. shot. The chamber burst with the first shot. The 3 1/4 Dram Equivalent load is 24 grains of “Infallible”.
Vol 19, Issue 2, Summer 2008, p. 18 - Destructive testing 1 Damascus, 6 Twist
Vol 20, Issue 3, Autumn 2009, p. 108 - Destructive testing 1 Damascus, 5 Twist “Bottom-Of-The-Barrel Wall-Hangers”

Total 28 vintage doubles/54 pattern welded barrels + 1 Fluid Steel Parker

A Parker GH with Damascus barrels and the Parker VH with Vulcan Steel barrels were the subjects of destructive studies in Vol. 10, Issue 4, Winter, 1999, "Finding Out For Myself" Part II and Vol. 16, Issue 2, Summer 2005, 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.
An as yet unpublished failure analysis and metallurgical study has been performed on both barrels by Ron Graham.

In reality a lesser density in the shot mat'l results in more pellets per ounce. The fly in the ointment though is in order to maintain any semblance of killing power it is necessary to increase shot size by at least two sizes. Thus 1oz of #4 steel for instance would contain less shot than 1oz of lead #6. With this switch you still end up with a lesser number of less efficient pellets. 1oz of #6 steel would contain more pellets than 1oz of #6 lead, but would be considered as more of a replacement for #7½ or #8 lead.

One of the leading duck hunting identities here is reputed to have had a container full of imported steel shells ready to sell even during discussions about lead's possible banning; he was all set to cash in once it happened...
Our supposed peak body here, the SSAA, seems not so fussed about fighting restrictions such as mandatory range attendances and club memberships for firearms licence holders. Guess who gains monetarily from those range attendances and club memberships?
If there's a buck to be turned - even at the expense of freedoms - someone'll put 'emselves there to turn it.

AMEN

I believe Roster owns the patent on steel shot wads. No surprise that he would promote steel shells. His articles in Shooting Sportsman rarely interest me.

Drew Hause,

Wow! Thank you for aggregating that! Those articles are a terriffic resource.

- Nudge

Wow. I was always a little suss on his opinions and pseudo science, as well as those parroting it; it makes perfect sense now.

Miller, you are correct of course, and that was a brain-fart on my part. A given volume of lead #6 shot as compared to steel #6 shot should be virtually identical in number because they are the same sized spheres, but certainly not in weight. At equal velocities, the lead shot will have significantly more foot lbs. of energy per pellet. Roster also claimed that steel shot which had the same kinetic energy as equal sized lead shot had greater killing power because it penetrated deeper. That seemed rather dubious and misleading too since the steel shot would have much less sectional density per pellet. If the steel and lead shot were of equal size, the steel shot would have to have a much higher velocity to have equal energy and it would not flatten any upon impact. But that is like saying that a full metal jacketed bullet has more killing power than an expanding bullet of equal kinetic energy just because it will likely penetrate deeper. He completely ignores the wound channel as a factor in killing. I guess he missed all the evidence of more crippling when waterfowl hunters were forced to change to steel. And I wonder which one is more likely to crack a tooth if you missed one while cleaning your game?

Keith;
You got it all right this time. I did calculate once sizes necessary to obtain equal sectional densities for steel comparable for lead & it was for the most part simply impractical to go to that large of shot for the given load vs game to be shot. Ballistic coefficient is of course the main factor in velocity retention but as all are spherical the BC is pretty much proportional to the SD. Obviously the reason steel has to be given a higher initial velocity is because it sheds it so much faster & we are primarily interested in retained velocity at point of contact. Muzzle velocity is of little consequence unless one is in the habit of shooting their game "At the Muzzle" of their gun. There is just no way steel is the equal of lead for shot.

Would make sense. I thought something must be going on.

I honestly don't understand Roster having a column at Shooting Sportsman. Here is a fellow who actively campaigns against lead shot and vintage guns. What he really seems to like is modern autos and steel shot. So why is he writing for that magazine? He would turn all of our vintage guns into museum pieces if he had his way.

He sure got us talking about him and the magazine, didn't he? I hope no one went out and bought an issue due to this discussion.

Here is some more of Roster's hogwash...

http://fwp.mt.gov/mtoutdoors/HTML/articles/2013/ShotgunWorkshop.htm#.VXCJB89VhHw

Interesting. In his steel shot lethality tests on pheasants, he thought that the overall wounding loss rate of 12+% was pretty good (I guess compared to waterfowl). Based on records I've kept of over 1500 wild pheasants shot and recovered (note: Roster's steel shot lethality test involved PRESERVE pheasants), I'd say that wounding loss rate is about 2 to 3 times higher than it should be.

The one conclusion he made from that study, with which I do agree, is that if you're hunting with a decent dog and you drop a pheasant inside of 30 yards, there's very little chance you'll lose him. Beyond 40 yards, your chances of losing cripples increase significantly. Distance increases aiming error, and the longer it takes your dog to get to a cripple, the greater the bird's chances of escaping.

But to my knowledge, there has never been a blind study done comparing the lethality of steel to lead on pheasants. Such studies were conducted on waterfowl.

Here is a copy of the article. I cut it down to make it fit better in a picture.

I guess the various European proofhouses don't do "sound science". They might be surprised to hear that from an expert witness.

Thank you Woody

NOT very informed

Winchester 1897 in 1904 H.H. Kiffe catalog

"The barrel of this gun has been proved with 9 1/2 drams of powder, and 2 1/2 ounces of shot."

British Definitive Proof 1855-1925 for 2 1/2” and 2 5/8” 12 gauge shells for a service load of 3 1/4 Dram Eq. with 1 1/4 oz. shot was 6 1/2 dram black powder with 1 11/16 oz. shot



Pete Dickey, “The Winchester Model 97” Feb. 1985 American Rifleman
Damascus barrels were regularly offered up until 1914 [but] cannot be considered “Smokeless Powder” guns.

1917 E.C. Simmons catalog "Bored For Nitro Powder"

The top is the edge of the barrel segment blown out at the time of a burst and the fracture is clearly ACROSS the crolle pattern; steel is grey-black, iron silver-white (3% Nitrol etched). The crack appears to be in the iron alternee.
The straight lines in the lower right are evidence of shear deformation at the time of the high pressure burst.
Additional metallurgical studies, including scanning electron microscopy, showed no corrosion and no low cycle fatigue.



More bad science?

Thanks Woody, very much for the piece by Roster. He does make it sound like either we're shooting short mags, or completely incompetent for everything else.

Larry, I know you're a big fan of the CIP and proofhouse system, but has your research dug up the science behind the 'brass hammer top lever standard' that our friends from the UK explained to Demonwolf for reproofing his Tranter patent gun. Roster may not be too worried about Europe, his agenda seems to be inclined towards the US.

Banc D'Epreuves Des Armes a Feu De Liege (Proof House for Firearms of Liege) appear to have determined a "standardized industry level of strength" for all the "rough forged tubes" that were placed on U.S. doubles
https://books.google.com/books?id=5fxGAQAAMAAJ&pg=PA52&lpg

First Obligatory Proof Load for “Double-Barreled Breech-Loading Sporting Guns” - 12g breech plugged tubes
21 grams = 324 grains = 11.8 Drams powder and 32 grams = 1.12 oz. shot

maybe because his drivel would go unpublished in Europe- certainly in the UK

there may be some here that would shoot unsafe loads in poor condition composite barrels- although its my guess they would do the same (or worse) in poor condition fluid steel barrels.

I tend to to move those that talk about the dangers of shooting Damascus barreled guns with smokeless powder loads because they were only made to shoot blackpowder loads quickly out of the expert category.

I only own two Damascus barreled guns one Parker and Belgian Guild gun. The Belgian manufactured a few years before WWI was originally proofed for smokeless. Looking at, and measuring its well care for bores, I'm reasonably sure it may have never seen a blackpowder shell. My Damascus barreled Parker was manufactured in 1924. It was proofed to the same standards as Parker fluid steel barrels. Again its well cared for bores likely have never seen a blackpowder shell.

I suspect; after the turn of the last century manufacturers of Damascus barreled guns knew that the purchasers were going to shoot smokeless loads in their new guns. It would seem even the manufacturers of inexpensive gun would design their guns for safe use with what ever loads were available. Without a doubt better makers of higher grade guns had reputations that they held in very high regard and would not knowingly make a gun dangerous to shoot with the newest and best ammunition available to their customers. By 1900 smokeless shells were widely available and in regular use.

Simple logic proves saying that Damascus barrels guns were only designed and meant to fire blackpowder means someone doesn't have a clue and certainly isn't an expert.

Parker Brothers 1893 Catalog
“Our guns are bored on the latest improved system for shooting Nitros, or Smokeless Powder, and all our guns are tested with some one of the most approved makes, and a tag accompanies each gun, giving the results of such a (pattern) test.”


1895 "All Bored For Nitro Powder"

I do use smokeless loads in damascus or Twist barrels with not much worry about their use. I would however like to make two comments to this thread.
1st; The type of powder originally used cannot be determined by the present condition of the bores. most users of quality guns in the black powder days understood the need for proper cleaning. The corrosive salts left by early primers was actually worse than that of Black Powder. The normal cleaning methods for BP took care of the primer residue as well. With the shift to Smokeless many were negligent in their cleaning. Consequently many early guns with pitted bores are more of a result of early Smokeless Shells with their Mercuric primers than actually from the use of Black Powder.
2nd; As long as an adequate wall thickness is present the actual "Boring" has little to do with the strength of the barrel. Many of the early guns were "Over Bored" for the use of all brass shells with oversize wads which were popular among black powder shooters who loaded/reloaded their own shells. I the early years reloading paper shells with Smokeless was discouraged. Thus guns intended for use with "Nitro" were bored closer to nominal gauge size for use of factory paper shells with standard size wads.
The fact they were advertized for such use of course indicates they were approved for use with smokeless, but the boring itself did not give an increase of strength.