Breech plug install

[romoshka]

Ok, so I’m the fool (see Parts and instruction thread) who’s going to complete this Ky pistol. So you can see the breech plug is hand tight but lacks a few degrees of rotation to be aligned. I will assume that vise and wrench will solve this but my machinist education tells me I should add some thread locker. Another additional option I see is to drill and tap the underside for a set screw with small brass plug against the threads. What say the more experienced builders here?

 

[Phil Coffins]

Use no thread locker. I don’t use anything on breech threads at all. Toque to aline then put a witness mark on the underside.

 

[ronaldrothb49]

You actually need to do the exact opposite. You need to put an anti seize grease on the threads. There is more to properly installing a breech plug then just screwing it into the barrel. You need to have the face of the breech plug mate up with the end of the bore sealing it at the same time that the tang on the breech plug mates up with the top flat of the barrel.

 

[SDSmlf]

View attachment 368941
Ok, so I’m the fool (see Parts and instruction thread) who’s going to complete this Ky pistol. So you can see the breech plug is hand tight but lacks a few degrees of rotation to be aligned. I will assume that vise and wrench will solve this but my machinist education tells me I should add some thread locker. Another additional option I see is to drill and tap the underside for a set screw with small brass plug against the threads. What say the more experienced builders here?

Big NO to the thread locker, rather time for some sort of anti seize.

Is the front of the breach plug bottomed out in the barrel? Guessing with your machinist education you were taught to use something like Prussian Blue to confirm fit. Also, loose the setscrew idea.

And not that it matters, but went through a Tool Maker apprenticeship years ago.

 

[Phil Coffins]

Having a good fit and clean machining of parts are all that’s needed. All though I am a hobbyist now my back ground has formed my process of fitting things together. After gunsmith school I worked with one of my instructors building custom ordered Sharps rifles. Opportunities changed and I became a tool maker for a major manufacturer for fifteen years. Then moved and did most of the manual machine work for a company that built race cars from the ground up for ten years. Many people that have tinkered at home have developed all sorts of short cuts and well meaning ideas about what they like to do. Most of it is un-nessasary and harmless as long as they do the basic good work to start with.

 

[ChuckJonesWagon]

My only question that your pic doesn't show is, is the breech plug fully seated in the chamber inside the barrel?

When I fit a breech plug I use a transfer agent to make sure the plug is tight agains the inside chamfer that the drill left.