NPM with IBM barrel pic needed......

[painter777]

I've been told that IBM barrels used by NPM have a punch mark.
I believe the punch mark would be near the P proof, IIRC.
I trust the source of this info.

I thouht I could just swap the no date IBM barrel from a SG receiver I have. Then buy or swap the SG for a late NPM receiver and be on my way.
Sounds like this isn't the case.

Can anyone show me a picture of this punch mark?

Appreciate any help.


TIA,
Charlie-painter777

Information

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[Denny779]

Here's my late NPM 4,299,xxx. IBM barrel. It's got the punch mark.

Click to view the original image

Regards,
Denny

[BrianQ]

Every single prime contractor used a different style or size barrel proof mark to indicate the carbine was proof fired. This is one of the ways one can tell if the barrel is likely the original one or if it has been replaced during a rebuild or restoration. There is more to it than finding a barrel made by the appropriate manufacturer with the right date. This is one of the issues most restorers over look. NPM used a punch mark, probably the same tool they used on the bolt and receiver. The location may or may not be near the barrel manufacturers proof. In fact depending on the barrel manufacturer and the time frame the barrel may not have another proof mark other than the NPM proof mark.

[painter777]

Thank You Denny.
So if that punch mark indicates use of that IBM barrel by NPM.

Would there be any other markings, like punch marks or different size stamped P's that would indicate that a no date IBM barrel may have been used on a Stan Pro or IBM.

I'm just trying to figure out what maker this barrel may have come issued on.

TIA
Charlie

[painter777]

I'm in the shop right now.......no books or Newsletters handy.
But didn't QHMC use the free barrel issue also...possible use of IBM barrels...

Charlie

[painter777]

I see no signs on a punch mark on this one.
The P is 1/16" tall.
Just curious I guess. This is the only IBM barrel I've owned.
Just trying to figure out what I can properly use it on.
I have multiples of many of the prime makers but not one of the NPM, IBM or Stan Pro versions yet.

Thanks for the help.
I'll keep digging.

Charlie-painter777