What are the the advantages/disadvantages to the Patent Breech?
Thanks!
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What are the the advantages/disadvantages to the Patent Breech?
Thanks!
The main disadvantage is they are harder to clean. The advantage is faster ignition. People argue about both, just like bevel up/bevel down or 9mm/45.
Patent Breaches are ideal for Percussion guns since the power from the Cap will blow through the Nipple into the chamber.That blow through does not occur with Flintlock ignition,therefore if you have a Flintlock with a Patent Breach it is wise to insert a pricker into the touch hole when loading to ensure a clear passage of the flame from the pan to the powder inside the breach.A larger touch hole than a nipple hole can be an advantage with Flinters to ensure good ignition.There is not a lot of power loss with the large touch hole.
As already noted, the big idea is better powder ignition there for better burn and more accurate shooting. If you check the rifles used in the 1000 yard matches both here and in world meets, all have a patent breach. Remember this means a very good wipe between shots to get the sludge out.
I'd put it more the other way around. Nock's patent breech was designed for the flintlock, in which ignition is weak, and slowed if the touchhole is filled with powder grains -hence the benefit of the pricker. The ignition of a small part of the charge in the patent breech chamber allows hot gases to squirt vigorously into the main charge. Even cannon benefitted from the chamber. I believe the gun which fired lead and fulminate of silver shells 5,500 yards in the siege of Cadiz, and was probably designed by that perfectly genuine artilleryman Napoleon, had a chambered breech.Quote:
Originally Posted by Col4570
Attachment 203604
But the percussion cap shoots hot gases deep into the charge anyway - but so momentarily that it isn't good at turning corners. In that situation the simpler and squatter shaped the powder chamber, the more efficient - just like when a primer must ignite the powder in a cartridge.
My issue with a flint patent breech is the possibility of powder bridging at the mouth ofQuote:
Originally Posted by Ballistics in Scotland
the chamber, preventing it from filling up with powder. Fouling around a square faced
breech mouth where it meets the barrel can cause the powder to collect there. Note how the mouth of the chamber(s) in the diagram has a radius edge the flares to the barrel wall to prevent that problem.
Much as any BP muzzle-loader needs cleaning out with hot water, the one I illustrated would need it much more. I think a common and better system was to have the powder chamber narrowed down considerably from bore diameter, but have the touchhole running directly into ito it, without that little almost closed chamber at the back.
i see absolutely no clear and wonderful ignition advantage to the patent breech for a flint lock gun.
i do see there is clearly higher maintenance work for cleaning and fouling control.
As for the cleaning.......get one of those small hand held steam cleaners, make an adapter for the nipple and let it rip. I have been using it on all my muzzle loaders since the post that talked about them and they work GREAT on patent breech barrels. I used to have a slotted rod tip and it would take a dozen or more patches to get that area cleaned really well. No longer now!
My double flint shotgun has patent breaches. The advantage is the ability to make the breach area wood a bit more narrow and be able to hold the gun better plus having someplace to put the touch hole other than the thin side of a shotgun barrel.. If you have ever shot one of the guns without the tapered breach plugs you will understand why.
I have seen the Nock dueling pistols wit the patented Nock powder chamber. If relibility was a question, non of the chambers would still exist.
And a big plus one on the steam cleaners
Yes I agree,the Breach Plug with a reduced bore is more positive for continuous ignition.The Actual Patent Breach with the chamber can have annoying blockage problems.Quite frankly there is little advantage in the patent breach and less trouble with a touch hole straight into the Barrel or into the Breach plug where in both cases the Flame is directed into the powder charge against the touch hole.My input is regarding Flintlock Ignition.
Original flintlocks sometimes had a gold or platinum lined touchhole, a bit smaller than the disc which sometimes surrounds a much smaller vent (entirely pointless in my opinion) in a percussion. If you were building from scratch it wouldn't be difficult to have those complicated little passages entirely lined with something like marine grade stainless steel or monel metal.
after-shoot cleaning isn't the issue, it's during shoot cleaning that can be a bugger, particularly if you have a need to shoot out-of-pouch. lots will depend on yer load - the powder type and granulation, and how well the patch, lube and ball work. also if it's a rifle, the groove depth and how it's cut. if there is a load or gun problem that requires fouling control, yer gonna need to clean out that patent breech and it ain't gonna be with a steam cleaner whilst yer on gong 7 of a woods walk.Quote:
Originally Posted by oldracer
this is not to say a patent breech will always wind up causing issues. typically they don't for me if i can conjur up a good load. most GPR flinters allow me a good dozen shots before i need to address fouling control.
Bottom fouling is indeed an issue. My main match shooting has been using a trade gun with shot for Quail walks but also shoot woods walk with it. It is a 28 ga shooting from 3/4 oz to 1 oz of shot. I do not introduce cleaning fluid till the end of the day. After a hundred shots or so the ram rod will climb a good half inch from the clean marks on the rod. I have built several of these guns and put the touch hole liner just up from the bottom. The reason is relilibility is a must, a hammer fall is a lost bird no matter the reason the miss fire. Twice through a woods walk [20 shots x2] shooting patched round ball is still not an issue. However I have done the same shooting a Thompson Center.
I make my Touch hole Inserts from Stainless Steel and cone them to bring the Powder Charge nearer the Pan.I usually make them 5/16 "BSF with a small Shoulder then file level with the Barrel.
That sounds very good. If it is a double you could have one continuous thread for those and the screw that holds the breechplugs together. If it is a it is desirable to avoid any little spaces where the tap tapers. I believe I would use an unthreaded cylinder secured with one of the bearing fitting grades of Loctite. If the touchhole is open on the right, and the hole is blinrd on the right, any force generated by pressure would drive it in, not out, like a tiny gun recoiling.
Attachment 204098
You can just see the Right hand Touch Hole as decribed above.
The Barrels are from a Breach Loading Gun,I squared off and fitted Sleeves into the Breaches,I made Breach Plugs that closely fit one inside the other to continue the lines of the top Rib.The Touch Hole Inserts are individual and coned as decribed previously.I have copied the specifications of original guns.The Lock Castings where from E J Blackley and Son,I made the internals and Springs.The Stock Was a Branch from a pear Tree.The furniture is Mild Steel Shaped and Case Hardened.A good Load is 2 3/4 Drams of BP and 1 1/4OZ of Shot.The Top Tang is from a Piece of Angle Steel shaped and Case Hardened.
Somebody has to do it? I suppose you mean that one breechplug has a curved cutout of the unthreaded part, centred on the axis of the opposite bore, so that the second breechplug can be screwed in? We don't ssee pearwood used much in stocks. It might not resist compression enough enough for something more heavily recoiling, but should be very stable, and nothing carves better.
Yes I built the gun during the 1980s,a friend gave me the Barrels,the other Parts for the Gun had long ago disappeared.I made the Plugs on my old Colchester Student Lathe using Silversteel,which I left unhardened but is tough since I did not want any brittleness at that pressure point.The Pear wood had been under my Bench for several years and had been painted with Wax on the end grain.A thing I noticed about the Timber was that it took the edge off my tools quickly,it originally came from a friends Garden,Someone else had the main Trunk but it was straight and did not have enough width,my piece was curved and ideal.I got the Barrels proofed at the Birmingham Gunbarrel Proof house.I Attachment 204122recessed the Plugs to fit the Mortimer Castings.
Attachment 204123 another view.