How it works - Smithsonian (patent model extractor)

U.S. Military Krags
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butlersrangers
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How it works - Smithsonian (patent model extractor)

Post by butlersrangers »

Looking at the sketches and reading the text of U.S. Patent no. 492212, I think, I understand an unusual structure that is quite different from the Krag mechanisms we are use to.

The bolt shown in the drawings has a bolt-face intended for a rimless cartridge.

Riding 'on' and traveling 'with' the bolt is a sliding curved-metal "Dust Cover". (#43)

The non-rotating "Dust Cover" is also the "Carrier" for the Extractor.
The long Extractor body (47) is fitted into a long dovetail, milled into the under-side surface of the Dust Cover.

The front part of the Extractor has curved-arms (#49) that partially encircle the Bolt.

When the Bolt is being rotated open, the Carrier and Extractor do not rotate.
During early-rotation, the rear of the Bolt's right Locking-Lug begins to make contact with the Extractor's right curved-arm, (starting initial extraction).

When fully rotated-open, the Bolt is pulled rearward. The right Locking-Lug pushes the Dust Cover/Carrier and Extractor to the rear, completing cartridge-case extraction.

(The other day, on another gun forum that discusses Krags, someone observed that maybe some members were no longer active, because everything had already been said on the subject of Krags ...... Secretly, I laughed and laughed)!
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FredC
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Re: How it works - Smithsonian (patent model extractor)

Post by FredC »

It seems like there was a Mauser with dual locking lugs before this one was made and patented? If so would Krag and Jorgenson been on the hook to pay royalties? Makes you wonder how many rifles were built till they got to the eureka moment with the bolt guide rib and the now legendary smoothness we all love.

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butlersrangers
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Re: How it works - Smithsonian (patent model extractor)

Post by butlersrangers »

'FredC' - I doubt the Mauser Brothers had a claim to "inventing" dual forward locking-lugs.

Off the top of my head, the French used this concept in the model 1886 Lebel Rifle. (It was their approach to containing the forces and pressures generated by their newly invented 'smokeless powder').

I believe Mannlicher and Mauser probably came along a bit later.
The 1888 German Commission Rifle, used forward dual lugs, (and that was probably more of a Mannlicher, than Mauser in design).
The 1889 Belgian Mauser used dual forward locking-lugs and may be the earliest production Mauser of that design.

I don't really know who gets credit for the dual-lug design.

Some of the Krag-Jorgensen smoothness probably goes back to the Jarmann rifle design, to which Krag & Jorgensen added a capsule-magazine.

There was a lot of hard work and evolution in the Krag-Jorgensen designs, that were adopted by Denmark, The U.S., and Norway.
IMHO - The Smithsonian 'patent model' probably has a lot of potential weaknesses and problem areas in the design.
Last edited by butlersrangers on Thu Sep 02, 2021 5:36 am, edited 2 times in total.

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butlersrangers
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Re: How it works - Smithsonian (patent model extractor)

Post by butlersrangers »

'FredC' - Here is a different 1850's approach to dual locking-lugs:
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Bernt
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Re: How it works - Smithsonian (patent model extractor)

Post by Bernt »

The drawings are for the 1892 Krag model with the double forward locking lugs. According to Haneviks book, it was deemed as unnessecarily strong during the US trials. It was cheaper to manufacture the standard Krag, and the strength was enough for the intended cartridge. The concept was soon left behind.

Here's the rifle in Digitalmuseum.
https://digitaltmuseum.no/011022699398/ ... ensen-1889

kragluver2
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Re: How it works - Smithsonian (patent model extractor)

Post by kragluver2 »

Mauser may have claimed specific design features of their dual lug mechanism but they did not patent the dual lug per se. As previous posters have alluded to there had been numerous dual lug systems that pre dated Mauser.

The Krag patent drawing being discussed in this thread had several advanced features not found on the US Krag. One of the Krag models tested during the 1891 Rifle Trials did incorporate a dust cover. There was not enough information in the description of the ordnance notes I found to determine if this was the same sort of dust cover as shown in the patent drawing. I am curious as to the timing of when the patent in question wad initially submitted. It was likely submitted during the midst of the 1891 trials.

Just looked it up... submitted June 1892.... towards end of the 1891 trials board. The patent drawing most closely resembles the description of Krag #4 except the dual lugs. Krag #5 and #6 were apparently the same as #4 but without the dust cover. #5 was the design adopted. #6 was said to be same as 5 except chambered for rimless cartridges.

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