LeFever Mainspring Compressor

OK, lets make something clear - I'm NOT a gunsmith. I have no qualifications other than owning a 1936 LeFever 20ga Nitro Special. I'm presenting how I solved the problem of compressing the two mainsprings to reassemble the shotgun. You accept all risk associated with working on compressed springs - I'm not responsible for the mistakes you might make. If you can't handle this task then by all means take your shotgun to a qualified gunsmith.

81 years ago my shotgun began life as one of a zillion very popular side by side shotguns manufactured by Ithaca and marked LeFever Nitro Special. Today it is still in use and is my favorite upland bird gun. But over the years, likely from over-oiling, the action got gunked up and I had a couple of light primer strikes. So I decided to disassemble the old girl and clean her up.

I've no hesitation disassembling my other firearms - in fact I think it is the best way to fully understand your weapon. But although the LeFever action isn't complex, it does require a special tool to compress the hammer springs, i.e. main springs for reassembly.

Yes, I could've just taken it to a gunsmith who had the tools, but then I wouldn't understand my shotgun like I do now.

So I'm going to focus on the spring compressor and skip assembly details.

First, here's a spring fully compressed - I just installed the hammer.

Here's a closeup of the same compressed spring

Here are two photos showing the general idea of the compressor

and here is general view of the hooks. The left hook rides in the cocking rod channel hole and the right hook grabs the end of the mainspring shoe.

Here is a close up of the right hook. Ignore the small groove. Use a V-file and cut a groove and shape a hook as shown.

Here's another view of the hook end.

And the all-important safety glasses. Can't stress these enough - your eyes are important!

Now a few details

The clamp is a 3" POC from Harbor Freight. The wire is 5/32" (0.090") piano wire available at ACE hardware. A hole is drilled in the clamp to locate and anchor one wire hook. The other hook is anchor by making a full turn around the clamp spindle (the end of the spindle was mashed off as it was in the way).

Pay special attention to the shape of the hook that will ride on the mainspring shoe - clearance is tight.

Pay attention to the length of the hook that will ride in the cocking rod hole - if it is too long it will push the cocking rod out a bit and you won't be able to align the hammer with the pin.

Size the hooks so that you can draw the spring up as far as shown in the picture with the usable range of the clamp. Remember to oil the spindle threads so the little POC lasts long enough to finish your shotgun.

Yes, shaping the piano wire is difficult. Pull on your big girl panties and use your muscles, vice, pliers, etc. but get it done. Don't scrimp on the wire gauge as it has to handle a lot of force.

Remember the safety glasses! You can shoot a spring into your finger - no big deal as it is just blood. But you don't want to lose an eye.