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Proof / Inspection stamping

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R6T8net View Drop Down
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    Posted: Dec 22 2016 at 7:22pm
I'm sitting here perusing the barrel section of the website and noticed that every proof mark appeared to be stamped prior to plating (my two examples are the same). One can conclude that either every example was a rebuild or barrel proof firing and stamping in fact occurred prior to plating. If the later is so then the barrels must have been tested independent of any other components; correct? Anyone willing to shed light on the actual process?

In studying my 2.89M Underwood I noticed the flaming bomb stamps (receiver behind serial# and on top of slide handle) and punch mark (in front of serial#) appear to be done post plating. Were these inspections done at the component or assembly level?

I'm a relative newbie and am hungry for knowledge (doesn't help that I own a mfg company and look at everything this way!).
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Dan Pinto, Photo Editor

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Post Options Post Options   Thanks (0) Thanks(0)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: Dec 22 2016 at 8:40pm
First and foremost, they are not plated. Plating I believe involves an electric current.

Very early carbines were done with Dilute, a form of bluing.
Then they were finished with the Parco-lubrite process which is a phosphate coating. Some call this Parkerizing.

Both chemically react with the metal and bond to the surface. The phosphate coatings hold oil better making them ideal for combat weapons.

The barrel manufacturer marks and date were done before finishing.
The inspection marks from barrel making process were also done before finishing.

The proof firing marks were done after the finish. At times you can see metal "in the white" around these marks.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RedSpecial Quote  Post ReplyReply Direct Link To This Post Posted: Dec 22 2016 at 8:42pm
Are you referring to the 1/16" P stamped on top of the barrel about four inches back from the muzzle? As I understand it, those were applied when the barrel assembly was proof fired. Some barrels were made as extras to the receivers so that they could be pumped over to other manufactures who were deficient on needed parts. In those cases those extra barrels were proofed when they were tested at the factory and then reproofed by whatever manufacture used it, which is why some barrels have two Ps stamped in them.

This is what I remember at least, and it could be I am remembering incorrectly.
-Neil
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Post Options Post Options   Thanks (0) Thanks(0)   Quote m1a1fan Quote  Post ReplyReply Direct Link To This Post Posted: Dec 22 2016 at 9:07pm
Been reviewing CCNL 361 Inland's 2nd serial number block, page 3:

As seen in earlier Inland sn blocks....barrels have punch mark on barrel in front of receiver. This mark was applied after finish application. Mark is similar to proof punch mark found on receiver in front of rear sight.....purpose unknown.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ghostman Quote  Post ReplyReply Direct Link To This Post Posted: Apr 01 2017 at 5:21pm
Usually a single punch mark is a mark left by the hardness test.
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