How to Repair a Black Powder Mainspring

Muzzle-loading weapons require black powder or approved powder substitutes to fire a round. These weapons have a lock mechanism operated by a mainspring which is used to cock the weapon. As with all weapons, wear and tear will cause mechanical problems, including a failing mainspring. This problem is often due to corrosion or breakage. If the mainspring is faulty, then it needs to be replaced. Replacing a worn or broken mainspring can be accomplished using a mainspring vise.

Things You'll Need

  • Padded gun vise
  • Mainspring vise
  • Replacement mainspring
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Instructions

    • 1

      Unload the weapon completely. Visually inspect the weapon to ensure that no ammunition or powder residue is present.

    • 2

      Secure the weapon in a padded gun vise. Ensure that the lock mainspring is accessible to work.

    • 3

      Pull the lock back to the half-cock position. Place the spring vise onto the mainspring. Tighten down the vise snug by turning the vise screw-head clockwise.

    • 4

      Lower the hammer gently. Pull out the vise and mainspring carefully. Discard the old mainspring.

    • 5

      Place the new mainspring into the vise. Turn the vise screw-head clockwise two full turns to compress the spring slightly.

    • 6

      Move the sear forward. This will make the hammer fall forward fully. Set the vise (with spring slightly compressed) into position. Ensure that the spring's long end is placed in the lockplate hole, and the protruding tab on the short end is placed in the bolster.

    • 7

      Pull the hammer back to the half-cock position. Turn the vise screw-head counterclockwise to release the spring. Remove the vise.