proof marks
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carbon outlaw
- Posts: 279
- Joined: Fri Jul 04, 2014 9:19 pm
proof marks
Ever noticed all the Proof marks ... this receiver and barrel came from two separate guns ... the P proof mark and alignment marks line up perfectly ... on the receiver and barrel have a look ...
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butlersrangers
- Posts: 9865
- Joined: Wed Oct 07, 2009 11:35 pm
- Location: Below the Bridge, Michigan
Re: proof marks
The hieroglyphics on the front of the Krag magazine box are likely worker and sub-inspector marks.
The markings probably verified the receiver had gone through various machining operations or had passed gauging.
During manufacture, approximately 125 machining steps were required to reduced a six pound forging into a 1 1/2 pound finished receiver.
The "P" stamp on the barrel and the "P" on the front edge of the receiver are proof marks.
The barrel and action were proofed separately.
Actually, the barrel was proofed as a "chambered tube", before it was rifled and a lot of machining was invested in it.
The special "proof cartridges" had little resemblance to the .30-40 round.
About mid-way, in the nearly 30 barrel making operations, a lug was bronze brazed in a dovetail, milled near the barrel muzzle.
This lug ultimately became the front-sight base and served as the reference point and manufacturing aid for the positioning of the barrel's Index Mark, the timing or 'clocking' of the barrel threads, and the locating of the rear-sight mounting holes.
When a completely finished Krag barrel was joined to a completely finished receiver, things were screwed to these pre-existing Index Marks.
This precision in Krag manufacture impresses me.
I have had the experience of putting three original U.S. Krag barrels on three actions. When the barrel breech-face 'bottomed' against the flange, inside the receiver-ring, the index marks 'nearly lined-up' or went just past the marks, within one or two degrees.
More importantly, the "head-space" was good, extractor slots lined up, and sight alignment was tolerable.
(IMHO - I would say your index marks are 'just a hair off'. No criticism, I would stop where you did. It is real close and good)!
The markings probably verified the receiver had gone through various machining operations or had passed gauging.
During manufacture, approximately 125 machining steps were required to reduced a six pound forging into a 1 1/2 pound finished receiver.
The "P" stamp on the barrel and the "P" on the front edge of the receiver are proof marks.
The barrel and action were proofed separately.
Actually, the barrel was proofed as a "chambered tube", before it was rifled and a lot of machining was invested in it.
The special "proof cartridges" had little resemblance to the .30-40 round.
About mid-way, in the nearly 30 barrel making operations, a lug was bronze brazed in a dovetail, milled near the barrel muzzle.
This lug ultimately became the front-sight base and served as the reference point and manufacturing aid for the positioning of the barrel's Index Mark, the timing or 'clocking' of the barrel threads, and the locating of the rear-sight mounting holes.
When a completely finished Krag barrel was joined to a completely finished receiver, things were screwed to these pre-existing Index Marks.
This precision in Krag manufacture impresses me.
I have had the experience of putting three original U.S. Krag barrels on three actions. When the barrel breech-face 'bottomed' against the flange, inside the receiver-ring, the index marks 'nearly lined-up' or went just past the marks, within one or two degrees.
More importantly, the "head-space" was good, extractor slots lined up, and sight alignment was tolerable.
(IMHO - I would say your index marks are 'just a hair off'. No criticism, I would stop where you did. It is real close and good)!