Tom Roster on low pressure loads and vintage shotguns.

Glad I had my 1891 Ithaca NIG out yesterday for one last time.
(shooting 3/4 oz, 1150 fps, 6200 psi hand loads)

https://shootingsportsman.com/pressure-vs-recoil/

So, Tom, how does the gun know if the load generating 7000 psi is a smokeless load or a blackpowder load ............hmmm?

SRH

I stopped caring what Roster thought a long time ago. Probably when he said steel killed ducks better than lead.

Sounds like someone is getting some free stuff for advertising!

That’s some pretty good fearmongering without much more than vague anecdotal heresay as evidence.

After a phone call with Tom a few years back about a test he did years earlier that proved, and quantified, pellet setback damage in lead loads to be varying according to the location of the shot in the payload, I came away with the distinct impression that he had gotten pretty full of himself. He was not the gentleman, on the phone, I expected him to be. Maybe he was just having a bad day, or maybe I was just too naive, but I'd not call him again.

SRH

A fact based rebuttal of sorts, with some wandering into physics 101, and contributions from Randy Wakeman
https://www.shotgunworld.com/bbs/viewtopic.php?f=2&t=505616

Only 1100 views so Roster's propaganda is obviously getting much greater market penetration.

1897 "FOR BLACK AND NITRO POWDERS"



1911 No. 1 Flues "NITRO POWDER PROVEN"

For those with American vintage guns, it's probably good to remember that in the early days of SAAMI, which came into existence in the mid-1920's, there were different proof pressures for guns with short chambers vs those with 2 3/4" chambers. Hunter Arms proofed their 2 3/4" 12's at 15,900 psi and the 2 5/8" guns at 14,300. (Also worth noting here that what was recorded as psi back then--and this information is from the mid-30's--was actually LUP. Pressure testing back then was still done with lead crushers vs the current transducers.)

Re CIP proof testing, anyone interested in doing that needs to be aware that the British proofhouses may still be reporting the pressures at which they proof their guns in LUP rather than psi. They were still doing that back in 2001, when I communicated with the Birmingham proofhouse. Fortunately, when it was clear that there was a misunderstanding, they converted the proof pressure in question (and the appropriate service pressure, which is even more important) to the American transducer equivalents. Their proof laws have changed since then, and we may now be speaking a common language. But anyone having a gun proofed in the UK would want to make sure of that. They may give the pressures in (metric) bars rather than psi, but if you're going to convert from bars to psi as measured by transducers, you need to make sure that they're talking transducer bars and not lead crusher bars--which they were still doing back in 2001.

Wakeman might be worse than Roster. He has opined that our damascus guns should be illegal.

This document states that the pressures are transducer BAR converted to PSI. Maybe the British are complying
https://www.scribd.com/document/97965210/CIP-Shotshell-Pressures

Somewhat stunning that the Tons to PSI conversion provided to Bro. Larry by the Birmingham Proof House in 11-2001 was simply Tons x 2240 x 1.33 and not measured.
I guess the Masters thought the numbers were close enough for us Colonials
2 1/2” / 3 tons = 8,938 psi
2 3/4” / 3 1/4 tons = 9,682 psi
3” / 3 1/2 tons = 10,427 psi
3” / 4 tons = 11,917 psi

Mr. Roger Hancox, Proof Master, Birmingham Proof House, 2008.
A basic “Rule of Thumb” conversion of tons to CIP transducer pressure (is) multiplying the tons per sq inch by 2240 to obtain psi, and then by a factor of 1.33 to obtain the approximate CIP pressure.

Mike George, Technical Editor, “ShootingUK”
http://www.shootinguk.co.uk/answers/what-is-fluid-steel-and-is-it-stronger-than-damascus-steel-13767
“In the USA there is one chap who is active on websites who believes that all Damascus steel barrels are so dangerous they should be destroyed.”
http://www.randywakeman.com/WhyYouShouldStayAwayfromDamascusBarrels.htm
“But then you are likely to get piffle like this from a nation that does not have gun barrel proof legislation.”
(Piffle: “pseudo-scientific trivial nonsense, baloney”)

sounds like what roster is saying is simply this:

if you must run smokeless loads through a gun designed for black powder loads, then, either:

a. have the gun proofed for smokeless loads, or

b. shoot the ammo the gun was designed for, black powder loads...

better safe than sorry...

makes sense to me...

or, you could obtain something like this, and have the option to shoot both black and smokeless..

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=563845&#Post563845

Ed, you may have trouble with this because you seem to have trouble with the science of CCH......but I'll still give it a shot.

The problem we have with Roster's "advice" is it is not based on science. Stan alluded to that in the first follow-up post.....how do the barrels tell the difference between 7000psi produced by black powder or by smokeless. The quick answer is the barrels don't. 7000 psi is 7000 psi. Yes, there are different burn rates that adjust the speed with which the pressure builds and then tapers off....but it's still 7000 psi.

For a guy who sells vintage guns, you sure don't know what side your bread is buttered on.

lot of inconsistency in the manufacture of cast and twist barrels... therefore, advise:

"better safe than sorry"...

and i do like to sell old guns, but also try to caution my customers, in order to keep them from hurting themselves...

Ed, not really sure what your first statement means. I also contacted Mr. Roster years ago and his excuse was " as long as shell manufactures say not to use their loads in Damascus barrel guns " that he was going to take the same stand. I pointed out to him pressure is pressure whether from a nitro load or BP load and maybe it was just cover your a$$ legal jumbo on the side of the box but he wouldn't budge. I quite reading anything he had to write.

blade, cast iron and twist steel barrels were mostly hand made by people with varying levels of skill...most were proofed for black powder, some were not...no sure way to tell how old black powder spec barrels will hold up to high pressure, without subjecting them to nitro proof...

also, if you tell some people that it is safe to shoot smokeless loads under 7000 psi, in a gun designed for black powder loads, guess what, they will forget about the 7000 psi part, and shoot whatever they think is best for their purpose...which, could create a hand held bomb...

I believe the warnings printed on shell boxes are simply to avoid "failure to warn" products liability lawsuits. I highly doubt shell manufacturers have done any research whatsoever on modern load suitability to vintage guns, you simply will never make it to a trial by jury if one blows up in your hands.

Any shells sold under SAAMI approval(pretty much all shells in the US) are mandated to carry this warning. This was decided at an industry meeting in the 1920's and remains in effect. The purpose in my mind was to sell more guns.

I read an interesting article about that meeting and how the warning became standard on American shotshells but I have no idea where I read that.

A.P. Curtis published a two part article in the July 1936 and the March 1938 American Rifleman entitled “Advantages of Short Shotgun Chambers” (courtesy of Larry Brown):
SAAMI, assembled in serious conference on March 26, 1937, passed the following resolution: “That an appropriate warning label be placed on all boxes containing smokeless powder shells, cautioning the consumer against using them in short chambered guns and also in guns with Damascus barrels and guns not in first-class condition.” The motion was made and seconded by representatives of two powder companies.
That same conference also passed a resolution requiring: “That all guns be marked so that the consumer will be able to tell the chamber length, as for example by marking 2 3/4 inch chamber etc.”

“These shells must not be used in guns with Damascus or Twist Steel barrels” warning appeared on shell boxes shortly thereafter.

Thank you Drew.
Steve

So easy to refute what he says. Buy RST shells. Shoot your vintage gun and enjoy. That’s it. Unless Tom Roster has more than conjecture to put out, I’ll just ignore him. I think Sherman Bell’s work was cased closed on the supposed danger of Damascus barrels.

Bell also clarified the potential danger from longer hulls (loaded to appropriate pressures) fired in short-chambered guns.

I once sent Roster an email with a question concerning bio wads. His response was a solicitation of money for the answer to my question. That was rather off putting. Now I wonder about the veracity of his work. I don’t see references or footnotes on what appear to be technical topics. His articles seem to simply be a flow of his beliefs.

Ed, I believe all the shotguns we're shooting were proofed either at the manufacture or at a proof house. That would take part of the first part of your argument. The second, if someone can't pay attention to 7000psi being safe, then so be it. That's like someone not adhering to the reloading manuals and their data. Does Lyman, Hodgdon, or Alliant refuse to publish data because someone will read it but reload something different ? Guess I'll just learn to ignore your childish banner.

paul: wood rather be accused of "childish banter", than being partially responsible for someone injuring himself, because i failed to warn him of the potential dangers of shooting modern ammo in old guns...

and the copying of popular doubleguns, complete with fake proof marks was a common practice in asia, africa and the middle east...

Title of the article is 'Pressure vs Recoil'.

There's no relationship so there's no reason for an article with that title.

I agree that it's somewhat misleading. I'd probably go with: "Pressure and Recoil: Potential Problems From Each".