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Jul 28th, 2025
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Joined: Sep 2007
Posts: 245 Likes: 3
Sidelock
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OP
Sidelock
Joined: Sep 2007
Posts: 245 Likes: 3 |
When I do a quick calculation using an average density for steel, the thickness of 60g of metal removed from the diameter of just one bore of these barrels would come to 0.072 thousandths. Meaning a negligible change in wall thickness from proof.
You might want to check your calculation again because .072" is .005" greater than the difference between a 12 gauge and a 16 gauge bore. That is hardly a negligible difference. Yes, 60g off of 1239g is a 4.8% change, which I agree is not insignificant. Hmmmmm . . . . The number I got was .072 *thousandths*, but I was a little rushed when I did the calculation and will recheck today.
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Joined: Jan 2006
Posts: 9,831 Likes: 494
Sidelock
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Sidelock
Joined: Jan 2006
Posts: 9,831 Likes: 494 |
No need for math.
The bore at the time of proof is marked just forward of the flats. What is the bore now?
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Joined: Sep 2007
Posts: 245 Likes: 3
Sidelock
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OP
Sidelock
Joined: Sep 2007
Posts: 245 Likes: 3 |
No need for math.
The bore at the time of proof is marked just forward of the flats. What is the bore now? Yes, but I won't be able to take advantage of Lloyd's generosity to make wall measurements until next Friday, and I was hoping to get an idea before then. Plus, as a former* engineering nerd, I wanted to have a little fun playing with the numbers. *That I screwed up the calculation illustrates why the word "former" is used in conjunction with the word "engineering" in the previous paragraph. And, I did find an error so ignore the previous number. I won't post my new results until I have gone over it a few times.
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Joined: Dec 2012
Posts: 3,685 Likes: 1119
Sidelock
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Sidelock
Joined: Dec 2012
Posts: 3,685 Likes: 1119 |
Shinbone: I will be there this friday, but fear that I may be out back-of-beyond next Friday now, chasing elk (old habits die hard). Can I get a rain check until the following week? I would like to see your gun in person.
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Joined: Sep 2007
Posts: 245 Likes: 3
Sidelock
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OP
Sidelock
Joined: Sep 2007
Posts: 245 Likes: 3 |
Lloyd - No problem on the timing. Good luck on your elk hunt, too. I am sending a PM
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Joined: Sep 2007
Posts: 245 Likes: 3
Sidelock
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OP
Sidelock
Joined: Sep 2007
Posts: 245 Likes: 3 |
Photos of barrel marking in front of the flats are below. I understand the gauge designations, but why the ratio and why two ratios for each barrel?  
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Joined: Jun 2008
Posts: 5,696 Likes: 226
Sidelock
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Sidelock
Joined: Jun 2008
Posts: 5,696 Likes: 226 |
Black powder proof, smallest internal diameter (16.9) Smoke powder proof, done later with a larger internal diameter from "Freshing up the barrels" (17.0) others are choke diameters (16.3 and 16.4) Mike http://www.shotguns.se/html/belgium.htmlSee proof mark chart 16th block down  1910-1924 Liege Degree of choke, in this case 0.7mm constriction
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Joined: Sep 2007
Posts: 245 Likes: 3
Sidelock
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OP
Sidelock
Joined: Sep 2007
Posts: 245 Likes: 3 |
Thanks. Why are the numbers shown as a ratio?
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Joined: Jun 2008
Posts: 5,696 Likes: 226
Sidelock
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Sidelock
Joined: Jun 2008
Posts: 5,696 Likes: 226 |
Why looking like a ratio??
I was NOT born yet in 1924
he he he
Enjoy the gun
How does it shoot?
Mike
USAF RET 1971-95 ![[Linked Image from jpgbox.com]](http://www.jpgbox.com/jpg/57865_80x60.jpg)
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Joined: Sep 2007
Posts: 245 Likes: 3
Sidelock
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OP
Sidelock
Joined: Sep 2007
Posts: 245 Likes: 3 |
Got it. Not a ratio, just choke diameter over bore diameter. Thanks.
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