Patent Breeches -- Benefit, Function, and Modern Variants

[Dphar]

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.

You could try one of the "vented" nipples I suppose.

Dan

 

[Old40Rod]

The Greener books indicates the Nock breech was developed in the 1780s...

The original question was "why the patent breech". I find Greener's idea of generating more heat vs. direct flame to be interesting, and plausible.

 

[xxgrampa]

dan, you are absolutly correct.

a hot shot nipple has a couple of side affects. first, the blast splits the cap. second, after the cap is split and as the blast leaves the bbl causing a lower press in the bbl (vacuum). the vent in the hotshot allow air to be pushed in and blow out the ignition channel..

as always ymmv.

..ttfn..grampa..

 

[Mike Brooks]

I've used some patent flint breeches that a friend of mine made, mostly for flint doubles. No ante chamber , just the vent liner hole bored at the bach of the powder chamber. The powber chamber has about 2* taper. They are fast, you can shoot them all day with out fouling out and they shoot hard. I'm guessing they have a higher velocity than a standard breech.
All that being said, They aren't any faster than my standard flint breeches, I can shoot my standard breech alll day with out fouling out and the velocity isn't so much faster that it makes a difference.
All of these patent flint breeches were mainly designed for doubles so they coud get the breeches closer[url] together....in[/url] my opinion, That and they had a new gimmick every one had to try out thus more gun sales. :wink:

 

[Dphar]

I've used some patent flint breeches that a friend of mine made, mostly for flint doubles. No ante chamber , just the vent liner hole bored at the bach of the powder chamber. The powber chamber has about 2* taper. They are fast, you can shoot them all day with out fouling out and they shoot hard. I'm guessing they have a higher velocity than a standard breech.
All that being said, They aren't any faster than my standard flint breeches, I can shoot my standard breech alll day with out fouling out and the velocity isn't so much faster that it makes a difference.
All of these patent flint breeches were mainly designed for doubles so they coud get the breeches closer[url] together....in[/url] my opinion, That and they had a new gimmick every one had to try out thus more gun sales. :wink:

I am not sure the recessed Nock is faster than my homemade liner in my 54. However. It has a 5/16 Whitelightning and can be shot indefinitely, well 20-30 shots anyway, with swiss powder with no hint of problems.
Someone needs to do some tests from the time the pan fires till the charge clears the muzzle. I watching the program on Manton that ran on the history channel (??) a year or so ago the recessed breech appeared to be faster in slow motion but it was not a extensive testing.

I proofed the "English" Manton/Nock breech the same day I proved an Italian 1803 Harpers Ferry. The 1803 barrel has liner of some sort. When proved the primer charge fired then I hear a "pop" from the touchhole before the muzzle blast. I assume this is a super sonic gas escape from the touch hole.
In shooting the 16 bore with the English breech, which has a larger touchhole, there was no pop. Does this mean the pressure at the touchhole was lower so it did not pop or that the muzzle blast so close behind the pressure at the touchhole that it drowned it out, or did the larger touchhole make a difference??. I just proved this breech again and got no pop this time either, but I was not paying much attention. Re-proof was due to replacing the first barrel.
This is why we need some high speed photos of this to make a accurate statement with no lag time added for the lock time.

Dan

 

[JOHN L. HINNANT]

Greetings All,

In my previous posts, the ignition problem that Rabbitt03 and I experienced with the Hawken Patented Breech on our TOTW Jim Bridger Hawken Rifles was briefly mentioned. There was also reference to a further modification that will hopefully negate the requirement for a vent hole in the bolster.

It is not an original thought, having been used on other rifles in my possesion. The final result
will be a combination of the Nock and Manton powder chambers.

Again. let me state that this Hawken Patent Breech is produced and marketed by a very reputable source. The casting and finished machining is of the highest level quality. In my opinion, the internal design is the root of the ignition problem.

The breech plug threaded tenon is 5/8" long with a 3/4-16 NF thread, with a powder chamber 1/4" long and 3/8" in diameter.

The shallow powder chamber causes the primer flash hole distance from the nipple to the powder chamber to be 5/8" long and about 1/8" in diameter. That is a long distance for a primer flash to travel.

It is my opinion that the long, narrow flash hole is prone to quick and easy fouling. Due to a definite safety issue, it is not possible to re-drill the flash hole to a larger diameter.

When Toney's rifle began to give ignition problems and finally no ignition, removal of the nipple revealed thst the flash hole was not merely bridged over with hardened fouling, but plugged solid.

Removal of the breech back at my shop further revealed that one half or more of the flash hole length was plugged solid with hardened fouling.

The quick, easy solutuin was to try venting the bolster. It worked. BUT as stated elsewhere a vented breech on the competition line is a pain in the guzzoo. It is the same as shooting a flint lock on the firing line.

Before fitting my breech to my barrel, the powder chamber was deepened to a depth equal to the thread tenon length. This shortened the flash hole a condsiderable amount.

In spite of my high expectations, the shortened flash hole contined to hold powder fouling and finally sealed off with hardened fouling.

Even "Hot-Shot" nipples did not help.

A 1/16" vent hole drilled in the bolster stopped that. Since drilling the vent hole, ignition has been quick and spontaneous without any msifires, hangfites, or no-fires.

BUT I DO NOT WANT A VENTED BOLSTER!

There has to be a solution other than venting the bolster.

It will be sometime (for me) before there is enough time to do my final modification with hopes of being able to do away with a vented bolster. Therefore, I will explain my idea, should any Forum members are having the same problem and want to give my idea a try.

My apologies Gentlemen. I have just been commandered for a "honey-dew job". And just when I was getting to the good part.

As General MacArthur said, "I shall return".

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!!!!

 

[feyx0006]

A cliffhanger on the ML forum!! Well, I'll be... :haha:

 

[Dphar]

Greetings All,

In my previous posts, the ignition problem that Rabbitt03 and I experienced with the Hawken Patented Breech on our TOTW Jim Bridger Hawken Rifles was briefly mentioned. There was also reference to a further modification that will hopefully negate the requirement for a vent hole in the bolster.

It is not an original thought, having been used on other rifles in my possesion. The final result
will be a combination of the Nock and Manton powder chambers.

Again. let me state that this Hawken Patent Breech is produced and marketed by a very reputable source. The casting and finished machining is of the highest level quality. In my opinion, the internal design is the root of the ignition problem.

The breech plug threaded tenon is 5/8" long with a 3/4-16 NF thread, with a powder chamber 1/4" long and 3/8" in diameter.

The shallow powder chamber causes the primer flash hole distance from the nipple to the powder chamber to be 5/8" long and about 1/8" in diameter. That is a long distance for a primer flash to travel.

It is my opinion that the long, narrow flash hole is prone to quick and easy fouling. Due to a definite safety issue, it is not possible to re-drill the flash hole to a larger diameter.

When Toney's rifle began to give ignition problems and finally no ignition, removal of the nipple revealed thst the flash hole was not merely bridged over with hardened fouling, but plugged solid.

Removal of the breech back at my shop further revealed that one half or more of the flash hole length was plugged solid with hardened fouling.

The quick, easy solutuin was to try venting the bolster. It worked. BUT as stated elsewhere a vented breech on the competition line is a pain in the guzzoo. It is the same as shooting a flint lock on the firing line.

Before fitting my breech to my barrel, the powder chamber was deepened to a depth equal to the thread tenon length. This shortened the flash hole a condsiderable amount.

In spite of my high expectations, the shortened flash hole contined to hold powder fouling and finally sealed off with hardened fouling.

Even "Hot-Shot" nipples did not help.

A 1/16" vent hole drilled in the bolster stopped that. Since drilling the vent hole, ignition has been quick and spontaneous without any msifires, hangfites, or no-fires.

BUT I DO NOT WANT A VENTED BOLSTER!

There has to be a solution other than venting the bolster.

It will be sometime (for me) before there is enough time to do my final modification with hopes of being able to do away with a vented bolster. Therefore, I will explain my idea, should any Forum members are having the same problem and want to give my idea a try.

My apologies Gentlemen. I have just been commandered for a "honey-dew job". And just when I was getting to the good part.

As General MacArthur said, "I shall return".

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!!!!

It would appear that the channel from the powder chamber in the breech to the base of the nipple is too small. The angle drilled breech is typical of quality perc breeches of the 19th century and was designed to reduce pressure at the base of the nipple. Thus drilling the powder channel .010-.020" larger to within 1/8" inch or so of the nipple base should cure the problem.
Breeches with large channels to the base of the nipple can result in nipples being blown out. It has happened and was the prime reason for some shooters back in the 1960s converting to flint. At least 2 anyway. A friend had a Bill Large breech in a Hawken that had a large "flash channel" to the base of the nipple. He finally had a nipple blow out and ended up with permanent black spots on his nose from imbedded powder fouling or grains.
One of the things you need to look at is the hammers contact with the nipple. It needs to be flat to give best ignition. I have built 3 pistols with the angle drilled TOW Hawken pistol breech and have a rifle with a TOW breech in a customers hands and have had no problems or reports of problems.
It is possible that you got breeches with channels that are drilled too small or that there is some other unknown fluke that is causing ignition problems. I do not believe the design is at fault.
I have never used either vented breeches or vented nipples. Though the British did do this sporatically in the percussion era.
On the other computer I have spme pictures of a pair of Joe Manton pistols with vented bolsters.

Dan