View Full Version : Patent Breech vs Breech plug
October 31, 2010, 06:16 PM
In the process of looking at the various repro Civil War muzzleloaders I see some of them have a patent breech and others, of the same model, have a separate breech plug. On a rifled musket designed to shoot minie balls is one system better than another?
October 31, 2010, 09:48 PM
I'm curious as to which models you are looking at that have a "patent" breech? Civil War muskets - '61, '62 & '63 models all have screw in breech plugs as does the Enfield (orignal ones). They do have forged bolsters - i.e. side bolsters that the nipple screws in to. The '42 model, Mississippi Model, etc. are like this as well. I bought one 1861 Repro. many years ago as I didn't want to use the originals I had in my collection. At that time, one of the manufacturers was making their barrels with a screw in breechplug that also had the bolsteer on it instead of the standard screw in breech plug. In reality, one would not be better than the other. When I hear "patent" breechplug, I think of a "hooked" breechplug. Not being critical . . . I'm just curious as to what you are referring to as a "patent" plug as there might be something out there I'm not aware of that someone is doing in putting their military models together. Thanks! :)
October 31, 2010, 10:32 PM
The Nock's or patent breech basically refers to the powder chamber that's cut into the barrel breech for faster ignition. It usually has an integral snail or bolster containing the flash channel that leads from the nipple to the powder chamber. This modification has been widely adopted and improvised upon and used in many modern muzzle loading designs to some extent including the modern CVA's. However drum type guns are differentiated by having a separate drum ignition system screwed into it instead of the integral snail or bolster. See the illustrations.
Yes, the Lyman GPR has what was once called a "patent" breech, the invention, IIRC, of the great gun maker Henry Nock. There is a sort of elongated hemispherical cut within the breech plug itself that is coaxial with the barrel. The diameter of this feature is about 3/8". There is a small hole that is drilled in the center of the hemisphere, again coaxial with the barrel, that connects with the cross hole in which the touch hole liner is installed. This sort of breeching was long ago found to give better ignition than letting the touch hole directly into the barrel, particularly when the more coarse grades of powder are used.
November 1, 2010, 03:51 AM
I'm curious as to which models you are looking at that have a "patent" breech? Civil War muskets - '61, '62 & '63 models all have screw in breech plugs as does the Enfield (orignal ones). They do have forged bolsters - i.e. side bolsters that the nipple screws in to. The '42 model, Mississippi Model, etc. are like this as well. I bought one 1861 Repro. many years ago as I didn't want to use the originals I had in my collection. At that time, one of the manufacturers was making their barrels with a screw in breechplug that also had the bolsteer on it instead of the standard screw in breech plug. In reality, one would not be better than the other. When I hear "patent" breechplug, I think of a "hooked" breechplug. Not being critical . . . I'm just curious as to what you are referring to as a "patent" plug as there might be something out there I'm not aware of that someone is doing in putting their military models together. Thanks!
I read it on a forum I was reading while surfing the net, it might be misinformation:) I am interested in an 1841 Mississippi.
November 1, 2010, 09:30 PM
I read the link you posted and I believe what is being referred to as a "patent breech" is the same as I referred to. Most military models had a standard screw in breechplug and the bolster into which the nipple is mounted, was a part of the barrel. Keep in mind that the bolster varied in the different models - the 1861 pattern had a clean out screw. The '62 and '63 models did not - they usually have an eagle stamped on the portion where the clean-out screw is located on the '61. The "61 bolster where the clean out screw is located is more "rounded" - on the '62 & '63, it is flat. I wasn't sure which manufacturer was making their barrels where the breechplug also contained the bolster and that portion was screwed into the barrel, but I think the link answers that in regards to the one with the "patent breech". I remember that the one I looked at had a "joint line" several inches ahead of the breech end of the barrel - something that you would not see on an original with the standard screw in breech plug. As far as the Mississippi - I've had the opportunity to shoot originals and a couple of repros. They are a nice rifle and the ones I shot were very accurate. I had a friend who shot one alll the time when we shot NSSA skirmishes. As far as shooting minie balls - you just have to make sure your ball "fits the barrel". I shot a repro. 1863 Remington Zouave years ago when I shot NSSA. I had a Lyman minie ball mold and I could shoot them "as cast" in my rifle with no problem - they mic'd about 575 and my bore was I believe about 577-578. I cast some up for my friend and he had to "size" them down to about 574 in order to be able to fire them and get them down the barrel during an event where you might shoot a quantity and have a problem with fouling. It all depends on your rifle. I will add that if your are considering using the rifle for re-enacting, you'd better check on what is allowed. The Mississippi, the Zouave, 2 band Enfield - are all shorter barrel lengths opposed to the 3 band Enfields, '61s, etc. I haven't re-enacted in a number of years but it used to be that you could only use 3 band muskets - primarily because when in a battle like, the back rank usually fires over the shoulders of the front rank. Good luck with your quest - whatever model you select, you'll have fun! Safe shooting! :)
November 1, 2010, 10:50 PM
Hello, olmontanaboy, The British Whitworth hexagonal bore .451 muzzle loaders used a Patent Breech..As well as the Parker-Hale re-make of same in the early 1980's. These were prized precision arms..a favorite of Confederate snipers.
November 2, 2010, 02:35 AM
I found the schematics of the breech of each of the Enfield rifles in question. Neither diagram illustrates the internal breech design. They only show that the breech of the Armisport is made from one piece (without a separate breech plug) while the breech of the Euroarms is made of two pieces which includes a separate breech plug.
Whether the Armisport is truly a patent breech design with a distict powder chamber is anybody's best guess unless they are familar with its actual internal design.
However, the patent breech has become a very generic label and very often simply refers to having a separate piece at the barrel breech that contains the bolster or snail and nipple.
In other words, both guns just might only have a simple flash hole that leads to the main powder charge and not into a separate powder chamber. But because the Armisport has a one piece unitary breech plug, it's being referred to as a patent breech simply because it looks like one. While the separate breech plug of the Euroarms does seem to indicate that it isn't a patent breech at all but certainly resembles what most folks would commonly call a patent breech if only by looking at its exterior.
I don't think that it really matters very much at all because they're not flintlocks, the musket nipple provides a hotter flash than a percussion cap does, and the caliber is so large that the powder load would burn just about as fast as a true patent breech ignition anyway.
It might even be arguable that the patent breech isn't always better, especially if very coarse cannon powder or such was being loaded. I mean who really knows what the performance really is?
Not too many people shoot cannon powder in their Enfields, but even if they did I don't really see how a patent breech would make much if any ignition difference with modern powder. Then there's the issue of which is the more original design, that is if there is any internal difference between them at all. At some point in the future, some Euroarms Enfield buyers just might appreciate having a removable breech plug if they ever want to get inside their barrel without needing to remove & replace an entire one piece barrel breech and lining it up properly. Just stating that for the sake of argument anyway. :)
The Armisport schematic is located on page 41 of this PDF manual:
Then 1853 Euroarms schematic is located on page 3 of this PDF manual, and the Euroarms 1858 breech looks the same:
November 2, 2010, 08:13 PM
Thanks for that information, very informative.
Euroarms = Barrel+Breech block+breech plug.
Armi Sport = Barrel+breech block no seperate breech plug.
I went to Gettysburg Battlefield Monday and stopped in Regimental Quatermaster http://www.regtqm.com/cgi-bin/cart.pl?db=rqmdb.txt&category=EnfieldP1853
And got to check out several three band enfields from Euroarms and two from Armi Sport. I was temped to buy one of the Armi sport Enfields:D, I was very impressed with the fit and finish of the army Sport models. Again, thanks for the great info.
November 3, 2010, 07:53 AM
The rifling is more important to accuracy than the breechplug. The patent breechplug will give higher pressure and more muzzle energy. However, pressure itself is useless if the rifling doesn't do its job.
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