Fed my Brittanies, made up some french press coffee, and leafed through Brownell's Gunsmith Kinks, volumes 1-4. As always, its in the last place you look...

Gunsmith Kinks #4 [ISBN 0976740931], pages 368-369 "Lefever Mainspring Compressor" is for the Nitro Special. Since it's in a smaller sized book, I don't hold much confidence that I can get a good scan of the facing pages with my flatbed scanner. Using ONE finger to type, I can transcribe the text and then scan the illustration relatively well.

It seems there are only three Nitro Special related kinks:
GSK #2. page 371, "Replacing Lefever Spring Retaining Screw"
GSK #3. pages 327-328, "Replacing Lefever Mainspring and Hammer"
GSK #4. pages 368-369, "Lefever Mainspring Compressor"

Brownell's Gunsmith Kinks volume #4, pages 368-369

Lefever Mainspring Compressor
by Clint Drumheller, Virginia Beach, Virginia

After rebluing a Lefever shotgun, I was faced with the problem of compressing the mainspring in order to install the hammers. I ran into the same Problem with a Stevens Model 311 about six months ago and here's how I did it.

1) The frame is secured to an angle plate with a C-clamp. Plywood or leather strips are inserted as shown to prevent marring of the finish. The face of the breech is placed on the top edge of the angle plate.

2) A pushrod is made from brass or aluminum rod. The diameter should be a little less than the diameter of the mainspring hole in the frame. Its end is filed to shape, as shown, to lock into the sear notch on the hammer.

3) The pushrod is chucked into the drill press and the clamped assembly of the frame and angle plate are positioned under the chuck. This is done by centering the pushrod into one of the mainspring holes. When this is aligned, the angle plate is then clamped to the drill press table.

4) The pushrod is then raised, the mainspring and plunger are inserted into the frame, the hammer positioned on the plunger and finally the pushrod is brought down and "locked up" with the hammer sear notch.

[Linked Image from ps-2.kev009.com]Illustration from page 369

5) The mainspring can now be compressed by lowering the quill slowly. When the hole in the hammer can be viewed through the hole in the frame, the quill is locked, leaving both hands free to insert a slave pin.

6) The quill is now released and raised, the angle plate unclamped from the table and the process is repeated for the other mainspring and hammer. Be sure to keep the pushrod aligned with the centerline of the mainspring.

Last edited by elric; 07/13/26 12:02 PM. Reason: Typing offline