casehardening Hawkens

[T*O*F]

The best method to protect the threads is to screw a large nut on them.  It also keeps that area soft when quenched because the greater mass slows down the cooling.  If you have a patent breech and want the powder channel protected, spot weld a plate over the end of the nut.

[Jim Kibler]

That sounds like a good proccess TOF.  I believe it would work fine.  I have heard of using ceramic caps to protect the end of shafts from carburization.  It seems covers such as this prevent sufficient gas circulation in the covered region to allow appreciable carbon absorbtion.

[Swampwalker]

I very much like the nut idea, TOF - I've got some cast of pieces of barrel that would work great.  A question though - why would you want to protect the flash channel in a patent breech - wouldn't the hardened surface be of benifit for corrosion protection?

[T*O*F]

I very much like the nut idea, TOF

It's not my idea.  It's how people who know what they are doing do it, instead of trying to reinvent the wheel.

why would you want to protect the flash channel in a patent breech - wouldn't the hardened surface be of benifit for corrosion protection?

Same reason as the threads.  You don't want any imbrittlement in the area that sustains the greatest concentration of the powder charge's energy