T.C. Factory Breech Plug Thread Size

[electro683]

I was told and wanted to make certain that all of Thompson centers 15/16" factory Hawken barrels in both flint and cap lock had a 11/16-20 thread. I wanted to take a factory cap-lock barrel and convert it to a flint-lock. So I wanted to make sure the threads are the same. Anyone know for certain?

 

[Black Jack]

Track of the Wolf sells these in 11/16x20. They state that it fits the factory barrel. They carry other thread sizes also, so I would call them to confirm what you need.

 

[Scota4570]

Pull the plug and measure it before you buy?

You will need a TC breech plug spanner,a real gunsmith's barrel vice, and fitted maple blocks with rosin. You will not get it out with a bench vice and cresent wrench.

I have no idea if the new plug will time properly. IF things are too far off the nose cap and wedge slot may be off.

 

[MSW]

what that fella said ... they are darn hard to get out...

I used a plug from Track to turn a perc. barrel into a flint, and the timing was a bit dicey, but do- able. You need the gear mentioned, plus a boatload of patience.

Additionally, the plugs from Track are slightly oversize, so you will need to file them smooth, and then of course you'll have to refinish the barrel. All of the stuff come off with no problem (sights, lugs, etc.) and go back on easily. I used Mark Lee's blueing to refinish, so I didn't have to fill the screw holes - just plug the muzzle.

Good luck with your project!

 

[Scota4570]

Pulled a Lyman plug today. I made an aluminum block to fit the curve of the bolster. I used sheet brass to protect the plug finish. My big wrench is massive, weighs at least 40#. IT uses two 1/2" fine threads bolts to pull the jaws tight. The handle is about 2' long. For the barrel side I used fitted maple blocks coated with rosin. My press is operated by a 20 ton jack.

The plug would not budge under my weight alone (250#). That is about 500 foot pounds of torque. I ended up rigging a rope stirrup to stand in while I wacked the wrench handle with a big hammer. It came loose! No damage to the blueing.

It can be done but you have to have the right tools and knowledge.

If I did not have the tools to do this job right I'd just buy another barrel and lock if I wanted my TC to go from percussion to flint. At that point you might as well buy a whole rifle.

I have not looked at a percussion TC carefully for a while. IF the clean out screw hole is centered on the side flat, you could just mill off the bolster and install a vent liner. I don't know.


I once converted one from flint to percussion using a bolster. Back then you could get a TC hammer. Converting was done like it was done historically. I wished I had not done that after.

 

[electro683]

I checked track of the wolf and they do not have a 15/16" flint breach in stock for the 11/16-20 thread. That is why I was trying to confirm that Thompson center used that thread for both the cap and flint lock barrels without having to pull it off to see since that is a very hard job. If they used the same thread , I have a flint barrel for the swap. Thanks