Miroku Shotgun Top Lever Conversion to Coil Springs

I have a wonderful , 40 year old Charles Daly / Miroku 12G Superior Trap shotgun.

Stock Photo…Mine has the raised cheek piece of a Trap configuration

The other day, shooting trap, I was 21 for 22 when the top lever leaf spring broke. UGH!!!

As I’m sure most of you are aware, leaf springs were used in many older shotguns, rifles and handguns. Today, most firearms have moved to coil springs.

I came home and searched wildly for a replacement top lever spring to no avail. Mr Wisner did not have the type I needed and had no idea when he would be making more. Robert Storm in Arizona has yet to get back to me with availability. These are the only two folks that could possibly help me out (I also ordered a package of flat leaf spring stock and quenching oil from Brownells to learn yet another facet of gunsmithing!)

Taking the shotgun apart, and looking at the action, I decided I might be able to convert this locking lug to coil spring. Sorry I didn’t take more pictures as I was developing the conversion. I think the pictures will explain it quite well if you are familiar with how the leaf spring was employed.

First thing I had to do was drill a hole in the locking lug to attach the device that would surround the trigger assembly and be pushed forward by a stout coil spring. Talk about HARD! That steel locking lug required a solid carbide drill and lots of cutting oil.

The brass screw head you see above is retained in the hole I drilled.

Next I had to fabricate the little part that goes around the trigger and will be pushed forward by the coil spring.

This little aluminum piece is drilled on the rear and a stainless steel pin is installed to retain the forward end of the spring.

And finally I turned a small brass button that resides in a hole I drilled into the rear of the action. This button also has a turned pin to retain the rear of the spring

So there you have it…Leaf to Coil! Lets hope this lasts another 40 years!

Share this Article:

7 comments on “Miroku Shotgun Top Lever Conversion to Coil Springs”

  1. Michael Graff Reply

    Question. I recently had a hammer spring break. Do you know of anywhere I can get a new one?
    Mike Graff

  2. Lyn Reply

    Mike – Status Guns in New Zealand have Miroku hammer springs. statusguns.com/status_miroku.htm

  3. Andy Trivette Reply

    Did you happen to draw up a blueprint on this project? If so would you share?
    Thanks in advance

  4. Raymie Reply

    Nice project .
    Might like to replicate this for my Miroku 700
    – where did you source the spring from ?
    – I’m assuming the retaining pip for the spring was threaded into the frame

    • Roy Bertalotto

      It’s been quite a while since I did this project.
      The spring was simply found in my junk box. I tried a few before I hit upon one that worked properly
      Sorry, can’t remember about the threading into the frame.
      Good Luck. Let me know how you make out.

Leave A Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.