Patent Breeches -- Benefit, Function, and Modern Variants

[feyx0006]

I have been searching the forum archives to learn more about patent breeches (an amusing aside... do a general internet search on the topic, and most of the useful pages are previous threads from this forum :thumbsup. As a good intro w/ good images, I refer you to the thread "Patent Breech" posted in Feb 2007. That thread discussed the Nock Patent Breech for flintlocks which brings ignition from the side flash hole, into an antechamber behind the charge, and through a forward-facing hole into a cone-shaped chamber containing the powder charge.

Most of our modern replica guns (T/C, Investarms/Cabelas, Pedersoli, Traditions, etc.) have patent breeches, and I wanted to know what they were and why. I now know generally what they are. However, I am not firing a flintlock, and I know my patent breech is not a "Nock" style for several reasons (it is part of the barrel and not the breech plug, no cleanout screw opposite the flash hole, etc).

So, I have a few questions:

1) Does the modern patent breech function similarly to the Nock design with an antechamber and ignition of the powder charge from the rear rather than the side of the charge?

2) Does anyone know the physics behind, and benefits of, the patent breech design?

3) Builders such as S. Nock included, what is the history of the patent breech? Any other good designers? Why design it?

4) I feel a definite shoulder about one inch from the rear-most end of the breech. The smoothly coned edges of classic patent breech images don't include this shoulder. I wonder about their design. Are the walls just a narrower cylinder w/ a flat bottom? Is the back wall actually coned down to a hole that delivers the flash? And what purpose would a flat-faced patent breech scraper serve against a tapered/coned breech end (other than gouging a circle in it)?


This is not a thread on how to clean a patent breech or which patent breech is more authentic than another. I really want to learn the nitty-gritty about the design, purpose, functionality, and "modern" application of the idea.

Again, I appreciate any insight you may offer :hatsoff:.

 

[CoyoteJoe]

Well it sounds like you pretty much know the answers. The Nock patent breech moved the charge closer to the prime and did no doubt speed ignition compared to the standard of the day. Whether it also increased velocity for a given powder charge, as claimed, I don't think was ever proved. I'm sure it was a pain to clean but then the servants could handle that choir.
The patent breeches on today's factory built guns have nothing at all in common with Noch's design except the name. They are just a counter-bored extension of the barrel, normally with an interior diameter considerably smaller then the barrel bore, and most commonly as you describe, just a square shoulder to the front. The effect is the opposite of Nock's design, by reducing the bore they move the charge farther from the prime. We compensate by using vent liners coned on the inside to bring the charge back to the prime. The most common form have the nipple bolster machined out in one piece with the plug. Some makers use a separate nipple drum threaded through the side of the barrel and into the threaded shank of the patent breech. Those generally have only a very small powder chamber, easily fouled and not easily cleaned.
The chief advantage is that it does make a stronger breech since drilling the barrel for a vent liner or nipple drum does weaken the barrel right at the point of greatest stress.
The downside is that they require extra effort to clean, generally best done with a bore brush of size to fit the recess in the breech plug. The percussion guns generally have a very small passage drilled between the nipple and the powder chamber. That small flash channel is subject to clogging which leads to misfires and hangfires.
I can live with patent breeches, have to really, but if putting together a barrel for my own use, I much prefer a flat faced breech plug with separate nipple drum if percussion. Drums of 5/16" or 3/8" normally come with a much larger flash channel than any patent breech and often they can be drilled out even larger. That assures that even Fg powder or coarse grained substitute powders will flow right in under the nipple for fast and certain ignition, never fouling up in a long day of shooting. And one can swab the bore all the way to the bottom, without need of a separate brush for the breech. It may not be as strong as a patent breech if you're out to see how much it takes to blow a gun up but it will be more than strong enough for any reasonable load, and even an accidental double charge.

 

[xxgrampa]

greetings fey,

a patent breech, is a breech plug where the ignition system is contained totaly in the plug, period..

a nonx, voorhiess or nock chamber design, is just that. a chamber design.

if the ignition system goes thru the side of the bbl, such as a drum or touch hole. then the breech is not a patant breech no matter what the chamber mite look like..

the roundball posted some very good pictures of the tc breech plugs. if you can find them, you will see how the complete ignition system is contained in the 'plug'..

howsomever, some say a patent breech is, a breech plug that has the tang attached to the plug..

have read both of the above in very reputable books. think it's a case of an author reading something somewhere, then pontificating on the subject, just like he discovered it.. they do that you know.. :rotf: :grin:

good luck with your research and ..ttfn..grampa..

 

[shortstring]

Several years ago another local gent & I did some chonograph work on this. His interest is in the shotgun so we worked with a 14ga antique damascus barrel. Much the same as Nock & Manton spent a great deal of time prefecting in the early 1800s. I set up the barrel with a cone shaped patent breech. As I recall the cone would have started at close to bore diameter & tapered to around a 1/4" around 7/8" deep where a touch hole met it from the side of the barrel. Not a true Nock breech but certainly a patent breech. We then took the same barrel & set it up with a flat bottom breech with a touch hole entering from the side. The patent breech shot around 10% faster than the flat bottom breech, same load. As I understand it the shape of the charge is what causes this. Joe Manton had a patent on a sabot for artillery that shaped the charge of powder in the early 1800s. I also have heard that a simular situation is happening in a Hemi engine. The word Hemi being short for hemispherical, describing the shape of the combustion chamber.

Paul

 

[MikeChapin]

I have three rifles with patent breeches, two percussion and one flinter. I know that they are supposed to help ignition and raise velocity. I have not seen any advantage to them in velocity or ease of ignition. The only advantage I have seen is on my flinter the touchhole has a little more bearing surface for the liner than it would on the bare barrel.

The disadvantage is that it promotes powder bridging in the barrel unless the barrel mating surface is tapered. This is rarely done on production rifles. This is not much of a problem with percussion ignitions but it can be a real pain with flinters.

A friend of mine was having a lot of trouble with his Pedersolli flinter. Bad bridging to the point where he had to push 4F into the touch hole to get it to go off. The problem was he wasn't cleaning the patent breech properly and the powder was bridging on the breech shelf. He keeps the chamber cleaned out now and the gun goes off fine. He still has some bridging once in a while but nothing like he had before.

If the breach face had a little taper at the meeting area the bridging problem could be helped.

 

[roundball]

I have three rifles with patent breeches, two percussion and one flinter. I know that they are supposed to help ignition and raise velocity. I have not seen any advantage to them in velocity or ease of ignition. The only advantage I have seen is on my flinter the touchhole has a little more bearing surface for the liner than it would on the bare barrel.

The disadvantage is that it promotes powder bridging in the barrel unless the barrel mating surface is tapered. This is rarely done on production rifles. This is not much of a problem with percussion ignitions but it can be a real pain with flinters.

A friend of mine was having a lot of trouble with his Pedersolli flinter. Bad bridging to the point where he had to push 4F into the touch hole to get it to go off. The problem was he wasn't cleaning the patent breech properly and the powder was bridging on the breech shelf. He keeps the chamber cleaned out now and the gun goes off fine. He still has some bridging once in a while but nothing like he had before.

If the breach face had a little taper at the meeting area the bridging problem could be helped.

It might vary with the different manufactures design or parts finish quality, etc...never had bridging in any on my TC caplocks back through the 90's, and am approaching the 10,000 shot mark with TC Flinters without anything like that happening...

 

[MikeChapin]

It might vary with the different manufactures design or parts finish quality, etc...never had bridging in any on my TC caplocks back through the 90's, and am approaching the 10,000 shot mark with TC Flinters without anything like that happening...

I've had bridging on my Tennessee on those hot, dry days when the breech gets caked up pretty good during a day at competion shooting. That rifle doesn't have a patent breech. When I built my .58 Hawken flinter, I sloped the lip of the breechplug. I very rarely have any problems with it. I only have to watch it when it getting a lot of use in competion on a hot dry day. We have a lot of those during the summer here.

You are right about the differnt manufacturers. My wifes' Seneca has sloping on the plug face. I can feel it when cleaning her rifle. I assume the Hawkens and Renegades are the same. All the Pedersollis I have looked at have a flat shelf where the breechplug meets the barrel.

 

[CoyoteJoe]

Some have a very small diameter counterbore but the T/C and it's Italian clones have a counterbore close to 3/8" diameter and not likely to bridge. Now the percussion flash channel is under 1/8" on all of them and that is certain to bridge but magnum caps usually eliminate hangfires, at least with black powder.

 

[Old Salt]

I suspect that improper wiping between shots ie. pushing a patch all the way down to contact with the modern patent breech would be the biggest cause of bridging. The patch pushes all the fouling onto the breech opening and leaves it there when you pull out the jag. Not much powder gets past that obstacle to the touch hole area.

I once owned a flint Lyman GPR that gave me ignition problems until I stopped swabbing between shots. After that the ignition was as fast as any custom rifle.

Old Salt

 

[Old40Rod]

Good questions! I did some internet searching on Google Books, and found some info. The source I found indicates that the patent breech idea wasn't to speed the ignition flame getting to the powder... just the opposite... it was about slowing the fulminate ignition flame down to generate more heat.

From 1907 copyright book by W.W. Greener, "The Gun and Its Development" (p. 118-119).. (I'm paraphrasing...) Apparently it was difficult to get consistent fulminate ignition charges in those days, and due to the "extreme quickness" of the fulminate flames, they could pass through a powder charge without igniting it. As a result, misfires were common, as was some powder being pushed out the end of the barrel unburned...

Enter Mr. Nock... he designed the Nock breech specifically to get a "front ignition" of the powder charge by hollowing out part of the breech plug so some of the powder charge was behind the touch hole to burn.

Greener goes on to state that later patent breech designs changed things like the position of the nipple to the top, and constricted the flash hole, all with the purpose of delaying the ignition flame and generating greater heat to give a more reliable ignition. He says this was all perfected to the point in 1850 that muzzleloading percussion gun was a "truly elegant weapon."

Very interesting....

I can't cut and paste the text, but you can find it on Google Books.

 

[Runner]

The in the barrel "patent" systems are strong. If the breech chamber is big enough or coned, they are very quick firing designs. They have one severe problem that pretty much makes all the decisions on how to clean and handle them for the user.
The Drum is screwed in thru a hole drilled in the side of the barrel/breech plug. Then the powder chamber is drilled from inside the barrel. The so called patent breech is now drilled thru the drum threads. Any oil or wet cleanign fluid used gets in the threads and collects at the end of the channel where the drum ends. In effect you have a small hole with oil delivery ports all around the patent powder chamber. The gun fires fine on the range, but when you go hunting, things change. The oil leaches out into the powder column because the gun is loaded for long periods when hunting. This causes misfires and hangfires.

As you can see from this old drum, even the end oil tank was exposed to the powder column on this gun.
The system needs special care to keep oil and other wet stuff out of the breach area and should be stored upside down with a paper towel patch rammed all the way to absorb and oil that is already in there as it leaches out!

 

[almrl]

Here's Ezekiel Baker's explanation on the patent breech.

Ezekiel Baker, Remarks on Rifle Guns, reprint of 1835 edition.

I. The patent breech was first suggested by me to the late Mr. HENRY NOCK in 1785. I had made many breech-pins to fit into sundry gun-barrels, to communicate the fire from the lock to different parts in the barrel; but I did not find anyone, in point of quickness or strength of shooting, to answer the purpose so well as the solid or joint breech, by which the fire was communicated to the centre of the barrel. This was so evident an improvement, that I advised Mr. NOCK to obtain a patent, which he did: and it was so highly approved of by sportsmen, that most of the gunmakers in England, as well as foreigners, attempted to imitate it. None of their improvements, however, as they termed them, were equal to the patentee's, whose barrels surpassed every other in point of workmanship. By firing the powder in the centre of the barrel, thereby lifting the charge perpendicularly, they produced greater accuracy and strength of shooting. By the old method of communicating the fire to the powder, the charge was driven out of the barrel in a zigzag manner, and this caused much greater friction to the centre of the barrel.

Interesting explanation (zigzag?).

Old Coot

 

[roundball]

And TC's implementation of their breech doesn't use the drum approach...they use a complete one piece breechplug with the "snail" design...excellent...as is the more simple Flint breech plug without needing the "snail" of course.

As far as I can see into the future, I have no plans to ever own a ML without a patent breech...they're fast, dependable, don't collect fouling, and no vent pick is needed on their Flint barrels..don't even know where the one is I bought 7 years ago as I never carry/use it

 

[JOHN L. HINNANT]

Good Morning feyx0006,

I have used the patent breech on rifles for 50 plus years and prefer them over the drum and nipple.

The barrel is wiped (not cleaned) between every shot with a Black-Solve dampened patch. Fouling IS NOT pushed from the bore into the powder chamber causing a build up, thereby affecting ignition.

In my observations and opinion, shooters having this problem are using a too tight fitting patch for wiping the bore between each shot.

Some patent breeches require venting of the bolster to keep the flask hole between the nipple and end of the powder chamber clear. The worse offenders are those designed with a short length powder chamber and flask hole that enters the center of the rear of the powder chamber. This design makes for a very long flash hole that fouls completely closed, in as little as 5-6 shots.

My friend Rabbett03 and I have Hawken Rifles using a very high quality patent breech. Unless they are vented, ignition is shut down in as little as 4 shots.

I modified my patent breech by deepening, enlarging the powder chamber diameter and coning the powder chamber to the Nock design.

This work greatly shortened the flash hole, which was the intention, but did not solve the problem. Clogging the flask hole continued until the bolster was vented, After that all ignition problems stopped.

My 1981 Uberti Hawken, JBMR, Ithica Hawken, and the patent breeches that I make, all have large diameter, deep powder chambers with flash holes that connect the powder chambers at a 90 degree angle. The JBMR and my shop-made breeches have coned (Nock design) powder chambers.

In each of these rifles, the flash is no more than 3/16's inch long, some less. Not one of these rifles have ever had an iginition problem.

NOT ONE of these rifles have a vented breech.

When cleaning the rifle at the end of a day of shooting, I ALWAYS use the flush tube method with Black-Solve solution. This is a 1/8 inch diameter clear rubber tube, 36 inches long, fitted over the nipple.

ALL fouling in the powder chamber and flash hole is completely dissolved and flushed out through the nipple and flush tube.

For exacting details on my full cleanup method,check out some of my older postings.

Best regards and good shooting,

John L. Hinnant

If you are not an NRA or NMLRA Member, why not? I am carrying your load.

Politicials LIE!!! USA Freedoms DIE!!!!

 

[Dphar]

So, I have a few questions:

1) Does the modern patent breech function similarly to the Nock design with an antechamber and ignition of the powder charge from the rear rather than the side of the charge?

2) Does anyone know the physics behind, and benefits of, the patent breech design?

3) Builders such as S. Nock included, what is the history of the patent breech? Any other good designers? Why design it?

4) I feel a definite shoulder about one inch from the rear-most end of the breech. The smoothly coned edges of classic patent breech images don't include this shoulder. I wonder about their design. Are the walls just a narrower cylinder w/ a flat bottom? Is the back wall actually coned down to a hole that delivers the flash? And what purpose would a flat-faced patent breech scraper serve against a tapered/coned breech end (other than gouging a circle in it)?



:hatsoff:.

The patent breech in percussion guns is safer and easier to clean. Drum and nipple breeches are manure from several perspectives.
Most modern patent breeches on the factory made guns are designed to be cheap to make and install.
I believe the Nock antechamber breech gives better velocity but experience is limited.
My Nock breeched 16 bore rifle would make 1750 fps with 140 gr of FFG Swiss and 1640 with 110 gr. Don't know how a flat or cupped breech would compare and won't be re-breeching it to find out.
My cupped breech 38" barreled 54 makes about 1900 with 90 gr on FFFG Swiss.

Dan

 

[Old40Rod]

By firing the powder in the centre of the barrel, thereby lifting the charge perpendicularly, they produced greater accuracy and strength of shooting. By the old method of communicating the fire to the powder, the charge was driven out of the barrel in a zigzag manner, and this caused much greater friction to the centre of the barrel.

This sounds quite similar to the physics of interior grannistand valves and muffler bearings.

:grin:

The W.W. Greener book quoted in my post above is extremely interesting and worth a look. Greener had an armsmaking company of the same name, and there is an entire section on damascus barrel making. Its all viewable online on Google Books. Whether his comments about the patent breech developments are true, I have no idea. I like his theory of changing the ignition flame path to generate more heat to set off the charge... at least it doesn't involve "zigzaging" and "friction" reduction.

 

[Hawken12]

I have a griffith patent breech,percussion.this is a cup in the breech,with the flash hole going to the centre of the cup at the bottom.The theory being ,the flash enters the chamber at the back of the charge and ignites in one direction ,forward.Rather than the flash coming in somewhere between the back of the load and the front,thus igniting both ways and then out,I bot into this idea and bot the breech.
In practice,the charge still goes both ways,one to the back of the nipple and the other out the end of the gun.After twelve to fifteen shots,I 'll get a misfire,I take the nipple out and the fouling is solid across the flashhole.so I remove nipple every 10 shots and ream it out and continue on.

 

[JOHN L. HINNANT]

Greetings Hawken12,

Your description of the problem with the Griffith Breech is one of the exact problems that Rabbett03 and I experienced.

The venting of the bolster solved that problem also.

I have a Hawken Griffith Breech purchased in 1984 that will soon be on a new Hawken rifle project. This breech came with the tang already precisely fitted and that fit-up is absolutely incrediable.

The quality of the casting of the breech and tang is the highest level and best quality I have ever seen.

When the Griffith brothers retired, they sold their machine shop business and the right to manufacture the breech and tang.

The new owner(s) evidently were not too successful, and the shop closed not too many years later. During that period of ownership, the overall quality of casting and finished work slipped quite badly.

The breech and tang manufacturing rights were acquired by a third party. During that time, the original casting patterns were destroyed in a shop fire. New patterns were made but were never close enough to interchange with the old breech and tang. In addition, the breech and tang were no longer factory fitted together.

About 2-1/2 years back, I ordered one of the new Griffith Hawken Breech/Tang without knowing of the above mentioned quality problems.

I was very disappointed with the overall product, particularly with the casting quality. The unit was returned in exchange for an R.E. Davis Hawken Breech and Tang. These are of very high quality.

I am told that the Peter Allen Hawken Breech Plug and Tang are also of very good quality. It is my intention to order an Allen unit to compare with other Hawken Breech Plugs and tangs being currently produced.

Rabbett03 and I have another idea for a modification that will hopefully solve the need to vent the bolster. When we get a chance to try it out, we report what we have done and the results

Rabbett03 and I shoot a lot of competition, and a vented breech is a pain in the gazoo on the firing line. We would definitely like to do away with a vented bolster.

And Old40Rod, correct me if I am wrong, but was not the Nock Breeching System developed during the flintlock period? That internal breech design would be a definite advantage in a flint lock.

But then again, I might be confusing the Nock invention with work done by the Manton Family.

Best regards and good shooting,

John L. Hinnant

If you are not an NRA or NMLRA Member, why not? I am carrying your load.

Politicians LIE!!! USA Freedoms Die!!!!

 

[Runner]

The smaller powder chamber idea is very old. Most of the gonnes and a lot of cannon use what is basically the same system with a different igniton. Patent dates often do not represent anything but when a certain person figured out a way to make money from something that was aleady common usage.

 

[Dphar]

The smaller powder chamber idea is very old. Most of the gonnes and a lot of cannon use what is basically the same system with a different igniton. Patent dates often do not represent anything but when a certain person figured out a way to make money from something that was aleady common usage.

The Nock antechamber breech does not just use the smaller powder chamber in the patent breech. There is a small chamber cross drilled at the touchhole and then a small passage to the main chamber in the breech/barrel. This was thought to give faster ignition or at least increased velocity. Since my 16 bore will move a one ounce ball at 1750 with only 140 gr of FFG there may be some truth to this. However, proof would require making several breeches which I am not likely to do.

Manton's recessed breech was also thought to make a faster system. At least from the point where the pan fired till the charge cleared the muzzle. However, its primary function was to narrow double flint guns at the breech.