Italian breech stamps

[Ike Godsey]

Ike, head space. The gap between breech face and a cartridge :thumbsup:


B.

thank you! :thumbsup:

 

[Britsmoothy]

Ike is giving a lot of good information on proofing, but the KG 1,320 and KG 1,920 do not match the 800 BAR figure that he correctly quotes.
27,000 psi or 19,000 psi are pretty different from
11,600 psi.

First, continental convention uses a comma to denote the location of the decimal place. We use a period. The period is used to group digits by 3's, as we use the comma.

Thus KG 1,320 is KG 1.320 (and 1.920)in American. And,the listings are a weight not a pressure KG/Cm squared. I began to wonder if Golfswithwolves was onto something, since 1 to 2 KG might be the weight of the barrels.

So I went to my stable of Pedersoli SxS's, and looked for KG numbers of the type pictured above. The two older guns had identical markings with similar numbers KG 1,340 and KG 1,840 (a 10 gauge). Using my kitchen scale, which reads in both metric and English with reasonable accuracy, I weighed both sets of barrels, and the weights matched the marking on the barrels. Spence, I would suggest that you try weighing the barrels and see if that confirms my findings.

Proofing involves an inspection of the set of barrels (every barrel is tested), and measurements of the barrel are taken at several points. Then, the barrel being tested is charged with a proofing load, that is a load of powder and shot (in shotguns) that has produced the 800 BAR pressure in test equipment. The proofing load is considerably larger than the working load would be for the gun. It is presumed that the load will produce a similar pressure in the barrel being tested. Then, the charge is fired and the barrel is remeasured to see if anything has moved or deformed. The proof house does not directly measure the pressure within the barrel being proofed.

Ike's English is far better than my Deutsch, but I am not quite sure what he means by saying that Black Powder can only produce a pressure of 800 BAR. I'm guessing that we can all agree that if we put 100 grams of FFFg in a typical BP shotgun barrel, fill then fill the barrel with cement, and fire the charge, that the barrel will burst. I haven't actually seen it done, but I've certainly read reliable documentation.

Sorry for the long post, but I am missing Paul Valandingham.

What did happen to Paul V? :hmm:

B.

 

[Lorne Johnson]

Spence's original question was what does the 18,3 on this barrel mean (metric equivalent of 12 gauge), and what do KG 1,320 and KG 1,920 mean. He also asked if those figures represented proof pressures. It is now pretty clear that the figures match the weight of the barrels, and are certainly not proof pressures. We agree that the proof mark is PN.

At least in England, the bore size is stamped on barrels after proofing so that if the barrels are bored out, a gunsmith can tell that the gun has been altered, and needs to be reproofed before it can be sold. Including a weight would provide a similar reference point for material being taken off the outside of the barrels. We are in heated agreement that it has nothing to do with the actual proofing process.

I happen to have 4 Pedersoli SxS's produced in 1978, 1981, 2005, and 2006 (as per the chart which you reproduced above). The older 2 guns have the weights stamped on them, and the newer two do not. Because your gun does not have the weight stamped on it, I am going to speculate that Pedersoli stopped putting such stamps on its guns before 1998.

Please note that I wrote that I was "not sure I understood you," not that you were "wrong." Thank you for your explanation. And, of course, we agree that one can blow these things up.

 

[Lorne Johnson]

Paul passed away, last summer I believe.

 

[Ike Godsey]

oh i see.
i have to apologzise. somehow i made a connection between weight and proof. but you're right, the original question was a different one.
so i hope it did not caused any harm to anybody...

 

[Britsmoothy]

Paul passed away, last summer I believe.

Thankyou, I had no idea! Shame

B.

 

[jdkerstetter]

....and why do some have the weights of the barrels stamped on them and some have the proof load pressures indicated as Ike demonstrated?

Why one or the other and not both? I have found published data C.I.P. standards on proof pressures but apparently each country is test to it's own standard, as long as it's higher. I have found nothing that indicates why barrel weights would be there and apparently it's not always. Making modification obvious seems to make sence.

This is all very perplexxing. :shake: Enjoy, J.D.

 

[Lorne Johnson]

It was always clear to me that you were being helpful, and that you presented a lot of good information.

 

[George]

Certainly, Ike, and you were quite helpful.

Spence

 

[Ike Godsey]

:redface:

ike