doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Win Model 12 Question

I use a home made wrench to latch onto the extension to remove and re-install them.
You need a bbl vise as well to securely hold the bbl w/o it turning,,that's a given for any of this work.
Wooden or lead 'jaws' work the best for me for that along with rosin.
Leave some clearance around a vent or solid rib just in case the bbl decides to slip while working on it.


The wrench shown is a simple piece of flat steel about 1" accross x 3/16 thick(?). It's about 14" long.
It's what it was as scrap when I picked it up to make the wrench.

The upper plug is a fixed position.
That is for the chamber plug.
It is easily removeable with the bolt screwed thru the handle.
Different size chamber plug for what ever gauge/chamber bbl you are working on.

A slot is milled below the fixed chamber plug position to accept a plug that can be adjusted the length of the slot.
This plug will be adjusted to fit into the magazine tube hole position reletive to the chamber of the bbl extension you are working on.

The plug is simply screwed onto a bolt from one side and tightened in position.
The diameter of that plug is made to fit closely into the inside of the magazine tube opening on the bbl extension you are working on.

You make different size magazine tube plugs for the different size frames needed.
You use the one wrench on all gauges with different chamber and magazine plugs
Works on 410 also on the Win 42.

Insert the upper chamber plug into the chamber of the bbl and the lower plug into the magazine hole in the extension.
Use the leverage of the handle to unscrew the extension,,the entire wrench pivots around the plug in the chamber.
Sometimes a tap in the end of the handle with a lead hammer breaks them free if stubborn.


I've used this for years when called on to dismantle a 12 or 42 bbl extension. Not a big M12 person, so the # worked over isn't a big one. But the system never failed and never damaged an extension.

Trying to simply wrench one off with an open end wrench of sorts will generally put a kink in the extension in that weak action rod cut...
In reality, most any work can be done w/o removing the extension anyway.