Patent vs Non-Patent Breech

[Old40Rod]

Thompson Center and Lyman's guns do not have a Patent Breech.

I guess this begs the question of how we are defining "patent breech". Is it "Nock's" patent breech? I didn't think there was is a "one and only" patent breech. In my mind, the term means any breech with the fire channel/flash hole incorporated into the breech, as opposed to flash hole (or drum) directly drilled through into the barrel.

 

[Zonie]

Old40Rod: IMO, if we are using the historic definition, Nock's Patent Breech is "the" Patent Breech.

As can be seen, Nock's true Patent Breech has a chamber which runs across the width of the barrel and is vented to the flash pan and the bore.
This chamber is quite large and is not to be confused with the flash channel that connects the vent or primer with the bore as is shown in the Chambered Breech.
The only modern production gun that I'm aware of that uses this is the Hoppe's Target Pistol (no longer in production). Of course it isn't that hard to make and I'm sure there are some modern custom made guns which have been machined using this design.
Mr Greeners Chambered breech is not a "Patent Breech". It was a different way to meet the same end, and it is the breech that is found in the Lyman, TC and some CVA's.

Now, as far as common usage goes, almost everyone who wants to talk about their Chambered Breech uses the term "my patent breech" or "TC's patent breech"... and in most cases they are not asking questions about its history or its design or the reason for its design. They are usually referring to some other question about their gun so most of us (myself included) ignore the mis-use of the term and deal with the question at hand rather than coming across as a wise guy and diverting the post towards issues beyond the one in the post.
Although this is great as far as being friendly and answering the question it does cause many people to come away with the impression that the gun does in deed have a true "Patent Breech".

When someone asks a question specifically about the Patent Breech, I feel it is only proper to use the historic definition which is Nock's design.
In the interest of making this a friendly forum I for one will continue to ignore the mis-use of the term unless it is the subject of the post.

 

[Old40Rod]

A fine explanation, thank you. Does anyone make/sell a true "Nock" patent breech anymore?

 

[roundball]

"...wants to talk about their Chambered Breech uses the term "my patent breech" or "TC's patent breech"..." "...mis-use of the term..."

Zonie, just a couple comments about implications in your post...I for one have never heard anyone ever say that a Lyman or TC patent breech was Nock's patent breech design.
And based on discussions I've had with TC staff over the years I never heard TC refer to their's as a chambered breech, as they've used the phrase 'patent breech' with me over the phone.
Because some of your statements seemed pretty matter-of-fact calling TC's design a chambered breech, I wondered if and who you might have talked to at Thompson/Center to have given you such cause for the statements?

If you've held TC's patent breechplugs in your hands and studied them thoroughly as I have mine, you'll immediately see that they are not designed like the 'chambered breech' in your drawing at all. The chambered breech simply has a shallow dish on top, then a single narrow one dimensional powder resevoir coming straight down, with a fire channel off the side of it.

By contrast, the TC plug design has two different size powder resevoirs under the shallow dish on top just like Nock's Patent Breech. The first is a wide large powder resevoir that comes down 2/3rds of the way, then it narrows to a smaller diameter powder resevoir that comes on down the last 1/3rd of the way, and that second powder resevoir "bottoms out" into the fire channel.

As I said earlier, TC's is a modified version of the Nock Patent Breech design...it is not designed like the chambered breech design in the drawing in your post...just wanted to clarify as I have the TC breech plugs sitting right here.

 

[CZMark]

Just to add a little confusion, CVA had a patent on its chambered breech design, which it properly referred to as a "patented breech".

 

[roundball]

Just to add a little confusion, CVA had a patent on its chambered breech design, which it properly referred to as a "patented breech".

I saw that too...chuckled at the play on words.
In Nock's case of course, the word patent had nothing to do with being patented, it was an adjective describing an open or unobstructed breech design.
So I thought CVA was pretty clever with their advertising terminology with that one :grin:

 

[prowler]

As I said earlier, TC's is a modified version of the Nock Patent Breech design...it is not designed like the chambered breech design in the drawing in your post...just wanted to clarify as I have the TC breech plugs sitting right here.

Roundball, could you post a couple of pictures or a sketch of the TC breech plug? I have a couple of TC's, but don't feel right about taking them apart. :shake: I've already taken too many things apart that never got back together right. :surrender:

 

[roundball]

"...could you post a couple of pictures or a sketch of the TC breech plug? I have a couple of TC's, but don't feel right about taking them apart. :shake: I've already taken too many things apart that never got back together right. :surrender:

Yes, TC breech plugs are not something to just casually decide to remove in the garage...you'll screw up the plug and the barrel unless you have specialized tools and know how :wink:

Heres a photos of a TC caplock plug...basically, the TC patent breech is designed likes Nock's breech but without the horizontal antechamber across the bottom.

1) Note the radius at the top of the breech...this is the "dished out" part of the drawings above;

2) Note right under the bevel you can see the wide mouth opening of a large diameter powder chamber...like the top chamber in the Nocks breech drawing;

3) That wide chamber goes down a ways then necks down smaller to a more narrow vertical channel resevoir, just like the narrow one under the large resevoir in the Nock's breech drawing;

4) The narrow vertical one bottoms out in a fire channel that is the same size as the narrow vertical one coming down to it, and moves off in a 90* angle to the right.

5) There is no large horizontal chamber across the bottom like Nock's.

 

[prowler]

Thanks roundball. :bow: You are truly a gentleman.

 

[J.D.]

3) That wide chamber goes down a ways then necks down smaller to a more narrow vertical channel resevoir, just like the narrow one under the large resevoir in the Nock's breech drawing;

4) The narrow vertical one bottoms out in a fire channel that is the same size as the narrow vertical one coming down to it, and moves off in a 90* angle to the right.

5) There is no large horizontal chamber across the bottom like Nock's.

So, what you have described is a two stage chambered breech, or more correctly, a two diameter chambered breech.

 

[roundball]

3) That wide chamber goes down a ways then necks down smaller to a more narrow vertical channel resevoir, just like the narrow one under the large resevoir in the Nock's breech drawing;

4) The narrow vertical one bottoms out in a fire channel that is the same size as the narrow vertical one coming down to it, and moves off in a 90* angle to the right.

5) There is no large horizontal chamber across the bottom like Nock's.

So, what you have described is a two stage chambered breech, or more correctly, a two diameter chambered breech.

I described what I described...I refer to it as a modified Nock's patent breech because of the obvious visual similarity.

If you have some private reason why you prefer to call it by some other name, you know the old saying...opinions are like noses so have at it

 

[CoyoteJoe]

Well I guess we'll have to disagree on "the obvious visual similarity" since I see no similarity at all aside from the fact that the breechplug is hollowed. The key points in Nock's design were the crosswise antechamber which brings the powder closer to the vent, and the small channel connecting the antechamber to the main charge which was intended to blast a jet of flame into the main charge to ignite it more instantaneously. The T/C design has neither of those features but actually moves the powder farther from the vent and assures that the main charge is ignited only at the very bottom. In practice the T/C design is just the opposite of Nock's.
I don't know if Nock's claims of faster ignition and higher velocity have ever been proved or disproved with modern technology, but one surely cannot extend Nock's claims to the T/C design, and that is where the distinction needs to be drawn. Call it what you please but do not try to claim the advantages Nock claimed for his very different design.

 

[arcticap]

If this CVA flash channel was widened out and enlarged to allow it to fill up with more powder like in some of the older CVA and larger drum guns, then it might be considered to more closely resemble the original Nock's Patent breech design. The other main differences would be that it uses a drum that's separately threaded rather than being integral within the chamber, and the clean out screw is on the other side and apparently much smaller in diameter.
Therefore this "modern" design prefers that smaller powder granulations and loading methods that introduce more powder into the flash channel be used.
But the more potent modern percussion caps do help to compensate.

 

[Zonie]

About Roundballs quote, "In Nock's case of course, the word patent had nothing to do with being patented, it was an adjective describing an open or unobstructed breech design.
So I thought CVA was pretty clever with their advertising terminology with that one " I beg to differ.

Nock's breech design was called "Nock's Patent Breech" because Nock Patented it in England. It was not an adjective describing the design.

The other designs that followed it at that time in history were intentionally made so that the makers would not have to pay Mr. Nock the royalties for the right to use his Patented design.

CVA wasn't in my opinion trying to make a play on words. Their design which has the powder drum passing thru the breech plug is indeed unique and I'm sure they Patented it.
Of course, their Patent allowed their Sales department to use the term to the fullest.

As far as I know, Thompson Center may have a Patent on their design as well.
After all, the stepped chambered design described by Roundball is rather unique as well.

As for me, when I hear the term Patent Breech, I first think of Nock's design. The prime reason for this is the design was a major highly successful idea which was used on many of the guns Nock produced in England. Also, it is Nock's design that is referred to and described in many books which deal with the history of firearms.

 

[Dphar]

Well I guess we'll have to disagree on "the obvious visual similarity" since I see no similarity at all aside from the fact that the breechplug is hollowed. The key points in Nock's design were the crosswise antechamber which brings the powder closer to the vent, and the small channel connecting the antechamber to the main charge which was intended to blast a jet of flame into the main charge to ignite it more instantaneously. The T/C design has neither of those features but actually moves the powder farther from the vent and assures that the main charge is ignited only at the very bottom. In practice the T/C design is just the opposite of Nock's.
I don't know if Nock's claims of faster ignition and higher velocity have ever been proved or disproved with modern technology, but one surely cannot extend Nock's claims to the T/C design, and that is where the distinction needs to be drawn. Call it what you please but do not try to claim the advantages Nock claimed for his very different design.

I have a true Nock breech in my 16 bore rifle and it will make 1640 fps with 110 gr vol of FFG Swiss from a 30" (breech included) barrel. This is with a 1 oz (.662) ball.
I have no idea what it would do with a flat breech.
It is pretty fast but it would require electronics to to prove speed.

Dan

 

[CoyoteJoe]

Dan, it just looks as though that breech design would be prone to fouling and hard to clean in the field, can you tell us of your experience in that regard?