Breech Plugs & Flash Holes

[Swamp Buck]

I have a builders question for someone.

Most all the muzzleloading rifle builders books & videos that I have read and seen, advise builders to fully seat the breech plug into the rifle barrel so none of the screw threads are exposed.

While watching the Chambers Muzzleloader Building video with Jim Turpin, a rifle is built where the touch hole is centered on the face of the breech plug requiring a portion of the breech plug face to be file tapered down into the threaded breech plug area to allow black powder to funnel into the flash hole liner.

My question is this; will this ever eventually lead to a problem with corrosion of the breech plug? Turpin and others have explained or written that this was a common practice on origional guns.

If corrossion is a concern or possibility, wouldn't anti-seizing grease that is put on the breech plug threads during its installation limit or prevent any corrossion?

 

[WRussell]

More experienced folks will hopefully chime in, but from what I've seen and read, corrosion of the threads is not that big an issue. A little anti sieze compound on the threads seems to go a long way.

The dictum of having the plug seat internally and externally at the same time is a goal to aim for if you're stiving for best quality work, but lots of servicable arms were built with no internal seat for the plug and the threads have lasted the centuries.

 

[Voyageur]

WRussel is correct. I went way overboard learning to be a custom machinist while learning to build firearms and my tollerances are measured in 'compression fits'.

Another item that surfaces is that the threaded portion of the breechplug is usually longer than it need be even considering safety margins. I suspect this is so due to the 'mass produced assembly' of some firearms.

If you would like a good, informed look at this issue: get Greener's book THE GUN or check it out through and inter-library loan. You'll see very clever breech designs that deal with what you are concerned with as well as maximizing the burning qualities of blackpowder.

His work got me started on breech modifications for flat breeched breechplugs.