Side Lock Patent Breech Improvements

[Bsharp]

I just got my Box Lock ready for a barrel.
The breech is similar to some Hawken's. [some]
The ones that have the angle drilled hole to the nipple.
First I run a 3/8" counter sink into the hole giving it a first taper, the blended the taper in with a flex shaft grinder.
This should nearly double the flow of powder to the nipple.

[D. Taylor Sapergia]

When drilling that angle hole from the plug's chamber to the nipple, one has to be very very careful not to come so close to the base of the thread journal that the hole blows out into the threads.  I have seen this on breeches I've had to replace.  Making an accurate drawing of what you have will go a long way to getting it right.  There's no trial and error here.

[Scota4570]

I refused to use a supplied Hawken plug.   The 1/8" cross drilled hole was a couple thousands from breaking out the base of the barrel threads.  I got  a blank casting, machined my own barrel threads, made the powder cavity deep, I intersected the cavity  with a cross drilled hole, and plugged the hole on the side flat.  That was how the quality English guns were done after all.   

Lots of guys use those cross drilled skinny holes and have good luck.  I see it as an invitation for misfires.  My first ML pistol was a CVA pistol done that way.  It was extremely unreliable.    I was not going to spend a hundred hours on an extremely authentic Hawken that was unreliable.