Metric & English Ammo ID Marked Barrel

[pjk9hp]

First time to see a "9mm x .752" markings on the barrel (ejection port) instead of the usual "9x19mm". What does the "13 TONS" represent?


Can anyone here identify the markings on the rear end of the slide?


source link: www.deactivated-guns.co.uk/deactivated-guns/allied-deactivated-guns/deactivated-wwii-inglis-browning-fn-hi-power-no2-mki-9mm-pistol/prod_3565.html

[Carolinaman]

Hello PJK-9HP,

"13 TONS" is the British Proof Testing of the barrel?

Chris

[abninftr]

They are British proof markings. You will find that 0.752 inches equates to 19 mm if you do the math (0.752 X 25.4).

[pjk9hp]

Jun 14, 2018 12:09:55 GMT -5 abninftr said:

They are British proof markings. You will find that 0.752 inches equates to 19 mm if you do the math (0.752 X 25.4).

Hello Mate,

Yes, I did the math before I created the thread. Perhaps I was anticipating a reply indicating a reason why they combined the metric & English measurement of the caliber/ammunition to be stamped on the barrel. From the previous post on schematic diagrams section, item 14 link of highpowercollectors.proboards.com/thread/281/power-schematics-parts-drawing-blueprints shows the blueprint for Inglis HP are in English measurement (except for the title of the drawing indicating "9m/m (.354) BROWNING AUTOMATIC..." 
I was wondering if the marking would have been ".354 x .752" on top then a 2nd line mark "9m.m. x 19 m.m."
I forgot having the C.I.P. in my file on proofmarks. Yes you (and Chris too) are correct, the "13 TONS" is part of British proof marking of the barrel denoting the pressure the firearm was tested in tons per square inch unit. The "CP " with a crown (slide marking) indicates "definitive proof for use with smokeless powders".

Thanks...

Attachments:

Commission Internationale Permanente Perma....pdf (443.39 KB)