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xausa
.400 member


Reged: 07/03/07
Posts: 2037
Loc: Tennessee, USA
Jeffery Under Lever Action
      #74744 - 28/03/07 01:02 AM

Looking through my copy of a 1930 Jeffery catalog, I came across their page dedicated to the Jeffery's .600 Bore.

The text reads, " We recommend the Under Lever Push forward Snap Action, as shown in this illustration, for all powerful Smokeless Powder Rifles." I have been aware of this representation by Jeffery for some time, but have never understood what they were talking about.

There is a German action, called the "System Roux", which appears to be identical to the top lever double underlug actions, except that it is activeated by an under lever rather than a top lever.

If this is the case with the Jeffery, then why should they write "It is a far stronger Mechanism than the Top Lever, and it admits of nearly ten times as much pressure being applied to withdraw the bolt as can be got from a Top Lever" and "The cocking, opening of the Breech, and ejecting of the fired cartridge cases are much easier with the Under Lever Snap Action than with the Top Lever."? I can't see why cocking, opening the breech or ejection should have anything to do with the location of the actuating lever, unless actuating the underlever cocks the hammers in addition to unlocking the breech.

The price, incidentally, was 110 Pounds. (Which translates to about $9939, allowing for exchange rate and inflation. Pretty good buy!)

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xausa
.400 member


Reged: 07/03/07
Posts: 2037
Loc: Tennessee, USA
Re: Jeffery Under Lever Action [Re: xausa]
      #75576 - 05/04/07 01:58 AM


Having received no answers to my question, I took it upon myself to locate an owner of an actual Jeffery rifle and managed to find one in (of course) Oz. Here is his response:

Bill

The underlever snap it is said to be (much) stronger than the toplever but I always thought that was only true of the Jones rotary U/L so I am not sure. Sounds a bit like marketing by Jeffery to me!! A combination of physics and geometry may produce the answer why I suggest as I am not sure on the snap U/L.

It is cocked by the barrels opening as per conventional T/L.

Regards


Fred Roberts

TR Group Pty Limited

Tel: +61 2 8289 5500

Fax: +61 2 8289 5501

Mobile: 0414 995 214

Email: froberts@trgroup.com.au

His web site (www.bestgunsaustralia.com.au/doubles.htm) has a lot of really nice guns, which are unfortunately well outside my price range.

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Otto
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Reged: 15/09/05
Posts: 111
Loc: Arizona, USA
Re: Jeffery Under Lever Action [Re: xausa]
      #75759 - 06/04/07 11:39 PM

Never seen the Jeffery gun, but I do have an Adams underlever in 450X3 1/4. The Adams uses what I believe is called a "Woodward spiral spring" action. It has two underlugs and a dolls head, and cocks with the underlever. Perhaps the cocking mechanism allows for fewer cuts in the water table...hence, a stronger action. Just a guess.
Otto

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xausa
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Reged: 07/03/07
Posts: 2037
Loc: Tennessee, USA
Re: Jeffery Under Lever Action [Re: Otto]
      #75958 - 09/04/07 01:53 AM

That is exactly the thought which occurred to me, since Krieghoff's claim of a stronger S/S action is based on there being no cuts in the water table to accomodate cocking rods/levers. Their solution to the cocking problem is to use a thumb activated cocking slide, which is far harder to actuate than a lever. It is the same principle they employ in their drillings with separate rifle barrel cocking, except that in a drilling, only one hammer needs to be cocked. Other systems used a separate side lever to perform the same task, leaving the tang safety in the traditional place.

I'm not sure how much sense this makes, since the real stress point on the action is the junction of the face and the water table, but there it is. A little spring in the water table might lessen the stress on the junction. Probably the best solution, if not the most aesthetically pleasing, is the Jaeger system used by Blaser and Merkel.

Thanks for your contribution.

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mehulkamdar
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Reged: 09/01/04
Posts: 3688
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Re: Jeffery Under Lever Action [Re: xausa]
      #76027 - 10/04/07 12:43 AM

Christopher Austyn discusses the Jeffery Snap Forward underlever system in his book Classic Sporting Rifles. He does seem to go with the Jeffery argument about the strength of the system. Do check the book out if you have a copy or if you could find a reference copy.

Good hunting!

--------------------
The Ark was made by amateurs. Experts built the Titanic.

Mehul Kamdar

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xausa
.400 member


Reged: 07/03/07
Posts: 2037
Loc: Tennessee, USA
Re: Jeffery Under Lever Action [Re: mehulkamdar]
      #76135 - 11/04/07 12:34 AM

Thanks, after seeing the book referred to elsewhere, I ordered a copy, which has not yet arrived.

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450_366
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Reged: 17/01/07
Posts: 1068
Loc: Sweden, west-coast.
Re: Jeffery Under Lever Action [Re: xausa]
      #76342 - 13/04/07 06:30 AM

Quote:

Looking through my copy of a 1930 Jeffery catalog, I came across their page dedicated to the Jeffery's .600 Bore.

The text reads, " We recommend the Under Lever Push forward Snap Action, as shown in this illustration, for all powerful Smokeless Powder Rifles." I have been aware of this representation by Jeffery for some time, but have never understood what they were talking about.

There is a German action, called the "System Roux", which appears to be identical to the top lever double underlug actions, except that it is activeated by an under lever rather than a top lever.

If this is the case with the Jeffery, then why should they write "It is a far stronger Mechanism than the Top Lever, and it admits of nearly ten times as much pressure being applied to withdraw the bolt as can be got from a Top Lever" and "The cocking, opening of the Breech, and ejecting of the fired cartridge cases are much easier with the Under Lever Snap Action than with the Top Lever."? I can't see why cocking, opening the breech or ejection should have anything to do with the location of the actuating lever, unless actuating the underlever cocks the hammers in addition to unlocking the breech.

The price, incidentally, was 110 Pounds. (Which translates to about $9939, allowing for exchange rate and inflation. Pretty good buy!)



I think what they mean is that if the pressure rises (cordite+high temp) and the brass sticks to the chamber plus the flex of the action it would be much more easy to use the strength of your hole hand and arm not just the thumb to whitdraw the locks.
Makes sens actually, you have more strenght just pushing your arm forward agains your other arm then using your thumb. And then when the thumb is not enough, change the grip and push it with the "muscle part" of the thumb.
I think it would also be more easy to whitdraw the cases with the one hand on the on the under-leaver pushing agains the other, and perhaps the stock put in the armpit. Instead of when finaly got the toplever to move sideways change the grip to add more strenght to the break.

Finaly i think that they write that it cocks with the push of the arm, but will when time is given check it up. If so this would be one more thing to overcome when breaking the rifle.
And the price, if i can remember right, (cant remember the year) was on the ,600 50 pound for the PH-grade and if you didnt want he ejectors 45 pound.
Damn, I realy, realy wanted to be born 100years ago

--------------------
Andreas

"Yeas it kicks like a mule he said, but always remember that its much worse standing on the other end"

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