Good Morning Roundball and All,
Ah, yes; the patent breech. Well done Roundball. You have definately given us ML Technocrats a good subject to kick around. For those who do not know what the Nock System looks like, would you please post the drawing that has been posted elsewhere on the ML Forum?
At this point, every post and commemtary has matched all of my experiences with the historic Patent Breech.
My first extensive experience with a patent breech was my first and only TC Hawken. While ignition was, for the most part, always good, the rifle simply would not shoot to the level of accuracy that I wanted.
Now fellow members, please do not bring out the hanging rope for me over that comment. I will make amends at the end of this post. That is a promise.
Now back to the patent breech issue.
As stated elsewhere, the Nock ignition system was originally designed for flintlock rifles, then later adapted to the percussion lock.
In 1971, I decided to machine a stainless steel one piece, long tang, patent breech using the Nock design. After 32 hours machining hours on the lathe and vertical mill, and a lare pile of stainless steel cuttings on the floor, it was done. (Yes, I know that I am slow, but I also was working with a piece of 2-1/2" diameter stainless steel).
A year later, the rifle was finished, and the shooting began. Some days, the ignition was perfect for every shot. Other days, it was irractic. After one particular fustrating day when finally, there was no igniton, I pulled the breech plug without doing my usual "flush tube" method of cleaning.
The problem was immediately apparent. The small diameter flash hole that was drilled into the center of the rear of the powder chamber was powder residue fouled and completely closed, as well as part of the connecting flash hole extending from the nipple.
If Roundball will repost the Nock drawing, you will see that when the Nock system is adapted to the percussion cap design, the percussion cap flash has to make two right angle turns before igniting the powder charge. The last right angle turn is though a VERRRY small diameter hole. In my case, that was the root of my erractic ignition problems.
To digress for a minute. The Nock system worked much better for a flint lock action, probably for two simple reasons.
1. Only one right hand turn for the flash from the
pan was encountered.
2. The powder charge vented backwards though the
vent hole at the pan with every shot. The
flint lock vent hole is much larger in
diameter than the hole in a percussion cap
lock nipple. This
venting kept the flash hole cleared all of the
way
back to the pan. I am sure, of course, all
other normal precautions were also taken to
keep the flash hole clear.
Normally, the percussion action muzzle loading rifle or pistol vents back through the nipple, keeping the flash hole clear. At least that is the theory. However, something as simple as a very strong main spring will clamp the hammer and spent cap tightly on the nipple preventing or minimizing the venting. Light powder charges that generate moderate breech pressures also can add to the venting-through-the-nipple problem.
Generally, venting the bolster of a patent breech or the drum of the drum and nipple system will solve that particular problem.
I solved my ignition problem by drilling the flash hole from the nipple AND the flash hole into the rear of the powder chamber larger.
Originally, the bolster was drilled with a #29
drill (.136") for a 8-36 NF clean out screw. The
hole drilled into the rear of the powder chamber
drilled to 1/8 inch (.128"). I was trying hard to be faithful to Nock design.
The clean out screw hole and flash hole was re-drilled with a #21 drilL (.159"), and tapped for a 10-36 NF SCREW. The flash hole to the rear of the powder chamber was re-drilled to 3/16" diameter.
The 10-32 (or 10-24) is the largest diameter that can be safely drilled into most bolsters.
After subsequent shooting test, the flash hole into the rear of the powder chamber had to be re-drilled to a larger diameter two more times before
the ignition problem was completely resolved.
The original 1/8" diameter hole at the rear of the powder chamber was first re-drilled to 1/4" (.250") diameter, then finally to 5/16" (.3125") diameter.
With the last re-drilling, all ignition problems stopped.
Well, so much for trying to remain faithful to the original Nock Improved Ignition System.
In all fairness though, maybe the same problems occurred when the flint lock action was replaced by the percussion caplock action. Maybe the original Nock design was also modified in a manner similiar to what I did. Who knows? I just know what was needed to solve my ignition problems.
I do know this. All of the English made rifles and locks that I have had the opportunity to examine were markedly superior in all aspects of craftmanship to the typical American crafted rifle.
As a side note; the 1835 Philadelphia made presentation rifle given to Congressman David Crockett is fitted with an English made back action lock. The gunsmith who made the rifle was noted for crafting superior quality rifles AND using English made locks.
Need to take a break for now, but will return to relate more of my person, good and bad experiences with the patent breech.
In closing, Let me express my highest regards for Mr. Thompson and Mr Center for producing the production QUALITY muzzle loading rifle for the American shooter. At that time, muzzle loading rifle shooting was near death in the USA. These two gentlemen rivived and saved the sport. While I do have some criticisms of their traditional rifles, I will NEVER throw stones at their product.
We all owe both gentlemen a huge debt for saving our sport.
Best regards and good shooting,
John L. Hinnant
If you are not an NRA or NMLRA Member, why not? I am carrying your load.
Liberal/Socialist Politicians LIE!!! USA FREEDOMS DIE!!!!
