dubble barrel flintlock

[bill perry]

I'm trying to build a 20ga dubble barrel flintlock bought w.c.scott barrels and cut the breech end so the chamber is 1 3/8" I just had a minchineist turn two breech plugs one off center. what is the best way to seat pugs aginsts barrels,  threads do not go to end of plug extention that will be screwed into barrels. how to cut metal on offset pug to fit smaller plug into barrels. ref. used for plug was book by william brockway.any info would be wecomedd.  best Bill

[Hungry Horse]

 I must warn you, that leaving a portion of the chamber in place may have an effect on your shot pattern. I have never done this with a full size shotgun, but did with a miniature trade gun I built for my you son, back in the day. When loaded short in the chamber, with the short barrel length (18") the gun shot a full choke pattern. When loaded beyond the chamber, it shot a cylinder bore pattern. This may not be so in a full length barrel, but it certainly was in the short .410 I built.

                            Hungry Horse

[bill perry]

plugs seat againts forcing cone

[Captchee]

 As you said , the face of the plug mates to the forcing cone  the back of the plug mates to the back of the barrel . The threads on the  plug need to be cut back to the  outer  part of the plug so that it will screw all the way down and mate to the back of the barrel .
As to cutting the  larger  offset plug  so the smaller plug will fit .
  I found the easiest way  to do it , is to not do it .  IE I use  2 small plugs with a  center rib attachment .
 But if you do the off set , then  you need to leave the small plug  long. That way you can  set in the off set plug  first .  Bring it around so that the off set lines  up  with the other barrel . Scribe the circumference of the bore on the off set .
 I then follow with a grinding burr . You only want your first cut out to be just large enough to  thread in the  smaller plug . Once you have it opened up , you then can thread  the plug down so that the back of it now comes down onto the off set plug .
 Now you scribe around the smaller plug , tracing the outline onto the off set plug
. Now carefully grind , then file  to the final line .
 If you  use an off set plug , that plug must be the first  one put into the barrels and the last one out of the barrels

[bill perry]

captchee  thanks for the reply I have the small and offset plugs .750 dia 16tpi the threads do not go al the way to the base of the plugs,how do I get them turned to the base. thanks,Bill

[keweenaw]

You buy or borrow a die and cut the threads to the base of the plugs, simple to do and takes about a minute a plug. Alternatively, but just as much bother, you can remove a couple threads in the rear of the barrel with a 3/4" drill bit.  This is scary because if the bit catches all your threads will be gone in an instant. There was an excellent tutorial on the old board that Cody did on how to breech these barrels, maybe someone remembers the location?

Tom

[Captchee]

 as Snyder said ,   use a die to cut the rest of the way

[JB2]

It's on the third page of tutorials in the old board.  Spent lots of time reviewing it too.