Pinning Breech Plug

[bezoar]

Japanese gunmakers would pin the unthreaded breechplug into the unthreaded breech and then pin in place.

Is this someting that would work good on a flintlock? And would it be a better way to breech that seamless tubing?

 

[Norskie]

Doesn't sound very strong, not enough load bearing surface. I wouldn't do it. Those Japanese guns are probably wall hangers.
Moose

 

[BrownBear]

Can you imagine the fit required to get a good seal?

 

[mbw907]

I don't think it sounds like a safe practice to me. I heard a few years back about the dangers of imported B.P. rifles and the breechplugs being pinned and some that were even welded in place. It's just too dangerous to consider. Good old threaded plugs for me, please. Be careful. :shocked2:

 

[Zonie]

IMO, using a pin to secure the breech plug is similar to having a small portion of one thread holding the plug in place.

In a design such as this (a pin) what you've actually built is a shear die which is trying to shear the pin into pieces.

When talking about the strengths of materials, we speak of tensile strength.
Simply put, that is the force required to rip the material apart when applying a stretching load to it. It is usually measured in Pounds per Square Inch.

An interesting thing about Tensile strength and shear dies. Because the die concentrates its force in one small area, the force to cut thru the material is only about 1/2 of the tensile strength.
This is the case with using a pin to secure the breech plug. The concentrated force where the breech plug and barrel meet will act on the pin like scissors and neatly slice thru the pin just when you don't want it to.

Don't do it.

zonie

 

[mbw907]

Amen on that Zonie. This sport is too fun for someone to get injured or killed just to save a few minutes time in the manufacturing process. You just can't beat the tried and true processes.

 

[MercerLake]

:shake: :shake: Consider that the breech plug is aimed at your face and all that would hold it back would be some weak wood. Oh no!!! I don't care how they proofed it I would not do it. :nono: :nono:

 

[Va.Manuf.06]

Japanese gunmakers would pin the unthreaded breechplug into the unthreaded breech and then pin in place.

The big question is, which Japanese makers? There are some very fine BP guns that have come out of Japan. Maybe this goes back to the early days of the matchlock, say 3 or 4 hundred years ago? I doubt that it is practised today. As all have said, not a good way to do a critical job and it is likely that those that did it learned the hard way... :shocked2:

 

[bezoar]

im refering tothe old japanese matchlocks made before whiteman came back to japan with commodore perry.

From what i can tell the breechplug is forced itot he barrela nd pinned in place. They used that up to well, till they stopped making matchlocks. And ive read that pins were used because Japanaese craftsman couldnt make screws.

I have seen photos of perfect ocndition guns still being used, and no issues with them into the 1930s. And they did make some 25-40 millimeter cannon with this breech.

but it was just an idea is all.

 

[eelclam]

My guess is that it would have been a shrink fit that is a cold plug forced into a red hot barrel breech or or even a plug wider at the face tapering toward the breech forced in with barrel being hammer formed around the tapper. The pin added later for security. I am in no way advocating its use.

Bob

 

[captgary]

Sounds to me like a really good way to have a really bad hair day.... :rotf: :rotf: :rotf: :rotf: