What kind of stock for breech plug?

[David R. Pennington]

I have a barrel, new old stock circa 1973 never been drilled for touch hole. Breech threads look good but plug threads have a couple places the thread has chipped off and has a funny little void or lathe center hole in front. Short story I am not comfortable using this plug. Considering forging a blank and making new one. I found an adjustable die same size as breech thread, 9/16-12. What type of stock should I use? I have some good wrought iron material. I realize the originals would have been wrought iron. I hear wrought threads should be swaged and not cut? What do you think?

[sz]

12L14 and 12L16 are both soft steels and they make fine plugs.
I would not worry too much about the alloy of the steel as long as it is sound and without voids.
I often make mine from 1018 mild steel.
A grade 5 bolt can also be used in some cases depending on what kind of plug you need.

[flinchrocket]

I think if you try to cut treads on wrought iron every time the cutter comes to a slag pocket it will
flip up a burr. When you swage the threads it presses past the pocket and forms the tread without
separating the metal around the slag pockets. I would use an old steel bolt to hammer one out of
and save your wrought . If you had a wrought barrel then you would want a wrought plug. IMO!

[gunmaker]

I use a #5 bolt, file a flat on top after in bbl. clamp a chunk of key stock to it---zap it with wire gun, remove and finish up welds grind/file smooth.   Flatten face of bolt 1st to seal breech face...Tom

[D. Taylor Sapergia]

I have a five foot long length of some shafting steel from a saw mill, 1 1/4" dia.  When I need a custom plug, I make it from this material.  It cuts well with a new hack saw blade and files well.

[David Rase]

Like Taylor, I have a length of 1 1/4" round 12L14 that I purchased from Online Metals.com.  Over this past year I have been upgrading my metal stock with 1018 and 12L14 cold roll steel and 360 or cartridge brass.  It is so nice to work with good material vs. welding shop grade steel.

The other upgrade was ordering a bunch of unplated wood screws from blacksmith bolt and rivet.
David