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 Working on the Marlin Lever-Action Rifle Sear
 by Roy Seifert

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Disclaimer:  This article is for entertainment only and is not to be used in lieu of a qualified gunsmith.  Please defer all firearms work to a qualified gunsmith.  Any loads mentioned in this article are my loads for my guns and have been carefully worked up using established guidelines and special tools.  The author assumes no responsibility or liability for use of these loads, or use or misuse of this article.  Please note that I am not a professional gunsmith, just a shooting enthusiast and hobbyist, as well as a tinkerer.  This article explains work that I performed to my guns without the assistance of a qualified gunsmith.  Some procedures described in this article require special tools and cannot/should not be performed without them.

Warning:  Disassembling and tinkering with your firearm may void the warranty.  I claim no responsibility for use or misuse of this article.  Again, this article is for entertainment purposes only!

Tools and firearms are the trademark/service mark or registered trademark of their respective manufacturers.


Working the Sear

Caution:  This procedure requires special tools.  Unless you are familiar with working with hammers and sears, please do not attempt these procedures.

Currently in my collection I have two Marlin lever-action rifles; a model 1895 CB in .45/70 caliber, and a model 1894 Cowboy Limited in .45LC.  Both sears were just rough cut as they came from the factory.  In fact, the sear for the 1894 CB Ltd. wasn’t even square.  I performed the following procedure to square and polish the sear, making the trigger pull lighter and crisper.

Required Tools
I never attempt to cut/polish a sear without the correct tools.  Without the correct tools I could round the surfaces making them unsafe and/or inoperable.  I used the following tools to work the sears on my Marlins.

Tool:

Available From:

Marvel 1911 Auto Sear/Hammer Jig

Used to cut/polish sear

http://www.brownells.com
Coarse ceramic stick

Used to coarse-polish sear

http://www.brownells.com
Fine ceramic stick

Used to final-polish sear

http://www.brownells.com
India Stone

Used to cut sear engagement surface

http://www.brownells.com
Hard Arkansas Stone

Used to polish sear engagement surface

http://www.brownells.com

Procedure

NOTE:  I Performed the following procedure before making any adjustments to the trigger return spring!

  1. I MADE SURE MY RIFLE WAS UNLOADED AND THAT THERE WERE NO CARTRIDGES IN THE CHAMBER OR MAGAZINE.

  2. Disassembled the rifle.

  3. Removed the trigger and sear from the trigger guard plate.

  4. Installed the Marlin sear onto the sear jig insert with the sear-to-hammer engagement surface up and parallel with the top edge, convex curve to the left.

  5. Inserted the sear jig insert into slot B of the jig so that the sear surface was below the top of the jig.

  6. Mounted the jig in a vise so that I could access the height adjusting screw, and the sear jig insert locking screw.

  7. Placed a ceramic stick or other flat object on top of the jig.

  8. Loosened the sear lock nut just enough so that the sear could rotate.
     
      
      
      
      
      
      

  9. Using a feeler gauge, rotated the sear until the back of the sear was 0.045” (45 thousands) away from the jig wall.

  10. Adjusted the height adjusting screw to check that the sear engagement surface was perfectly flat against the flat object.  Rotated the sear until the engagement surface was perfectly flat and parallel with the top of the jig.

  11. Tightened the sear lock nut making sure the sear did not rotate.

  12. Used a felt-tip marker to mark the sear engagement surface.

  13. Took a few strokes with the ceramic stick to ensure the surface was flat.  Adjusted until the stick removed an equal amount of marker front to back.  This indicated that the surface was flat.

  14. If the engagement surface was square, i.e. the entire surface touched the flat object, I could go to step 17.

  15. If the engagement surface was not square, I cut it with the India stone.  Adjusted the height adjustment screw and cut the surface until it was perfectly flat and square with the top of the jig.

  16. Polished with the hard Arkansas stone.
      
      
      
     
      
      

  17. Polished the engagement surface with the coarse ceramic stick until it was shiny and flat.  Kept the polishing surface wet with water.  Ceramic sticks use water as the cutting agent.

  18. Final polished the surface with the fine ceramic stick.  Again, used water as the cutting agent.

  19. Dried the sear and applied a light coating of good quality gun oil.

  20. Reassembled the rifle.  The trigger was now a bit lighter, but very crisp.

If the trigger was not light enough I could now adjust the trigger return spring tension.

Final Note
I’ve fired maybe 300 rounds through my 1895CB before taking it apart to obtain the photo for this procedure.  I examined the sear engagement surface and found it to be solid black.  This indicated that the entire surface was engaging the hammer, i.e. the sear engagement surface was flat and square to the hammer engagement surface, which was as it should be.

 
   © Copyright 2008 Roy Seifert.