Removing a Bisen

[Peter Bleed]

How hard is it to "unload" a Japanese matchlock?

I have a couple of tanegashima that I have never "unloaded." Are there tricks and hints that I should know about before trying to remove the "bisen" bolts?

Peter

[Bugyotsuji]

A very good question, Peter. My gunsmith tells me that although it may seem like a horrible thing to do, he fills the gun barrel with water and puts the breech into a bucket of said water, so that it can seep through the vent hole. (Too many have exploded while he was playing with them, he said.)

 

Bolt-headed breech screws fall into two basic categories, those that will open with a bit of encouragement, and those that won't. The former are no problem, but the latter can generally be opened with judicious use of a massive vise/vice, although there are some that will simply break under the strain. I have given up on only one. I poured penetrating oil down the barrel daily for three months and used wrenches and rubber hammers and leather whips and Zorro masks and all kinds of encouragement in daily sessions, but it is still rusted shut to this day.

 

The other approach is use of a worm jag, a kind of screw on a pole that will lock into a lead ball, enabling it to be pulled out.

 

Use of an external heat source is naturally not recommended for use with a loaded gun, but it can be useful for removing the bisen of an unloaded one, provided that there is no zogan inlay near the breech end.

Melting inlay is one problem, but another is gouging by the vice. I have seen terrible vice/vise scars on a barrel. Use wood blocks,  etc.

[Brian]

I have 3 guns...one a relic and 2 that are pretty decent. Not one has ever given up its bisen. I have tried all the tricks in the book. Eventually I gave up.
Just my luck.

[paulb]

I think I need glasses for the early morning. The title had me trying to guess why anyone would want to remove a larger herbivore with a Teppo and from where (eyesight or senility not sure which)

[Bazza]

I see absolutely no need to remove a bisen for either a loaded or unloaded gun.  I couldn't stand to see the inevitable very disfiguring gouge marks.  Piers' suggestion "The other approach is use of a worm jag, a kind of screw on a pole that will lock into a lead ball, enabling it to be pulled out."  This could be used after a thorough bronze brush cleaning of the barrel with an additional feature known in the panel beating trade as 'knock hammer"to assist the removal power of a worm jag.

Good luck Peter.

 

BaZZa.

[Brian]

Bazza...
A solidly blocked flash hole. Because it is curved..resists any attempts from the outside and cannot be drilled. removing the bisen allows one to inspect from the inside and see if something can be done. Otherwise you are working blind. Also, a "through cleaning" is far more effective than trying to clean a blind hole, and you cannot change the direction of a decent brass brush.

[Peter Bleed]

Once again NMB has worked. First level sources make bisen removal  sound easy and routine, but the reality seems to be more complex.

Thank you all. I'll be in contact!

Peter

[Peter Bleed]

14 hours ago, paulb said:

I think I need glasses for the early morning. The title had me trying to guess why anyone would want to remove a larger herbivore with a Teppo and from where (eyesight or senility not sure which)

Paul,

This quip had me buffaloed for a moment, but as a Plainsman, I figured it out.

P

[Bugyotsuji]

Paul, Bisen must the plural of Bison.