Chamber wall thickness with 16ga Krupp steel

[Thomasg]

Today I examined a very beautiful old Knoth Drilling in a 16ga over 9.3x82R. The shotgun barrels are of Krupp steel and of course 2 and 9/16" chambers. The client had a prestigious gun company examine the arm and was told that the wall thickness in the front end of the chambers averaged only .070" and was too thin in their opinion to be safe to shoot.
I found the barrels to be in excellent condition and see no reason why 2 and 1/2" RST shells cannot be used safely in the shotgun. This is probably due to the fact that I view Krupp steel to be superior steel.
Am I wrong in my opinion on this?
Tom

[sharps4590]

I don't know the dimensions of my drillings or combination guns but I bought them to use....and use them I do. They are variously from before the first German proof law in 1891-93 up to just before WWII. I cut back 2 3/4 hulls and load my own.

[mike ford]

Thomasg,
Once a gunsmith (especially a prestigious one) is employed to examine a gun for safety, you can expect it to be declared unsafe or if declared safe, it would be by a substantial safety factor. To do otherwise would endanger their insurance coverage. Once you buy a gun that has been declared unsafe, you have taken the liability unto yourself. To then sell it to someone else, would require pretty "iron clad" language acknowledging that the gun is unsafe to fire. This would reduce the value to the point that it would be hard to sell. To sell it without the acknowledgement would be very dangerous.
Mike

[Thomasg]

Hello Mike
I appreciate your response and do not disagree. I have worked in this industry for 46 years now. I questioned this "gunsmith's" findings only due to the fact that they may be making their assessment based upon modern SAAMI American specs and not original German specifications, much of which is unknown to American gunners. In the written report they gave the customer they did not even take the time to educate him on the chamber dimensions of the shotgun barrels. When I asked him about this he said nothing of the sort was discussed with him. I take issue with anyone who, due to lack of knowledge "errs" on the side of caution and dismisses something as unsafe without the proper knowledge to do so.
Even after 46 years I am still learning and will never know everything there is to know about the vast array of firearms and it's history. When I read the assessment on this fine old gun the lack of detail jumped out at me and I understood why the client was left wondering. Had the statements been made about Damascus barrels I would have re-enforced the assessment, but to dismiss out of hand Krupp steel barrels in good condition in my view was a disservice to the customer.
As always I do sincerely appreciate your feedback and observations.
Tom

[Thomasg]

I did find this information,
"The Hunter's Encyclopedia from the German proof house: minimal wall thickness at end of chamber, regardless of length, for 12, 16 & 20 gauge guns should be 2.3mm (.0906") for 'ordinary good steel' or 2.1mm (.0827") if a 'Special Steel' was used."
Which leaves me scratching my head as to why KRUPP, of all companies would make barrels with a forward chamber wall thickness of only .070"? Worth noting the chambers have not been altered.
Tom

[mike ford]

Thomasg,
I don't think Krupp made the barrels, instead, I think they made they made the steel from which the barrels were made. Krupp logos were often added by others to advertise that they used the famous Krupp steel when making the barrels.
It should be noted that at one time rust inclusion free Damascus barrels were considered superior to steel. Some steel barrels were made with a fake pattern to simulate higher priced Damascus barrels.
Mike

[Thomasg]

That's it right there..!!! That was the kind of knowledge I was hoping to get by exploring this and I really appreciate your response Mike. Thank you very much,
Tom