Can I tap my barrel for a breech plug, or do I need to use a lathe?

[David R. Pennington]

I went to an estate sale a while back and wondered into the basement. I found box after box of old carbon steel taps and dies from machine screw sizes up including some in the range we are talking about for breech thread sizes. Some are sets with plug, taper and bottom taps. Some were rusted and ruined but most still packed with oiled paper in original packing and ok. I should have enough to experiment with when need arises to breech a barrel. This is all good info and appreciate all the knowledge being shared on this thread.

[Acer Saccharum]

FYI, Carbon taps are more brittle than HSS. They break easier. However, if a carbon tap is broken in a lockplate, you can anneal the broken piece and drill it out. Not possible with HSS.

[James Wilson Everett]

Guys,

With the original tooling the tapered threads were made with an adjustable split die tool.  With this tool the smith can make the taps and the male side of the thread joint to whatever diameter he wishes.  This is not possible with modern type tools.  Here is a photo of a late 19th c/early 20th c adjustable die stock.  I am sure that you can see how a tapered thread could be made with this.  Also, the breech plug male thread can be made to give a really good thread fit with the breech of the barrel.  If the joint is too tight, just reduce the male thread diameter a bit - simple.





Here is a scan of an 18th c adjustable die stock for making larger diameter threads, works similar to the more modern one above, but I haven't been able to find one outside of a museum at a reasonable price.




Jim

[Mark Elliott]

Jim,

I really appreciate the antique tool info your provide.   On a side note,  where did you git the die stock shown above.   The reason I ask is that I am pretty sure I have a tool or two marked R. Hoyt.   I think one of them is my hand vise.

[James Wilson Everett]

Mark,

I can't remember where I got this tool, probably from some antique shop in W. Pa. or W. Va.  It looks to me that the R. Hoyt stamp is from the user or perhaps the hardware salesman.  The stamping from the tool maker is a lot more precise & professional looking, while the R. Hoyt is quite bit out of line.

Jim