Pedersoli Patent Breech design

[Fly103]

I've got around 600 balls thru my pedersoli pennsylvania rifle now and and there seems to be a common theme regarding the patent breech. On the first 2 or 3 shots of a shooting session when i pick the vent after loading i can feel the powder in the breech. After a few shots I notice when picking that the breech chamber is empty, not fouled or anything, just empty. I pulled the vent liner to verify and discovered the powder charge packed between the ball and breech plug face. If i poked at it thru the breech chamber with a bit of wire, dry grains of powder readily dropped right in the the chamber. When firingvwith the breech empty vs full i havent noticed any appreciable delay in lock time so the flash is still easily reaching the powder in the barrel.

I guess my question is, has anyone else noticed this and is the air gap behind the charge vs between the ball and powder dangerous? To me it seems as the barrel heats up in the humid air the little bit of condensate and fouling causes the powder to stick to the breech plug face rather than enter the breech chamber. Ive noticed when shooting in the dry air environment of an indoor range the problem goes away completely. For the last few range sessions i've just ignored the happenings to no ill effect. My standard load is 50-60gr of 3f goex.

Thoughts?

Chris

 

[Grimord]

I always bump the off side of the lock with the heel of my hand after I have dropped the powder down the bore. I give the gun a few stout raps to settle the powder in the breech area close to the touch hole. Haven't had any ignition problems when I do this. Now it is just a habit and part of my loading procedure.

 

[Fly103]

Grimord, Ive been doing the same with mixed results.....sometimes i get powder in the breech, sometimes not. Either way she goes bang without delay.

Chris

 

[hanshi]

I'm one of those shooters who does not like patent breeches at all. I cannot understand why they dominate the factory market when they, IMHO, offer no noticeable advantage nor a reason for them. But I have to say my two Pedersoli never gave me any problems at all.

 

[Larry Akers]

Contrary to hansi, I like patent breeches. I use them especially on the target pistols I build because a patent breech will give more uniform pressures which gives more uniform velocities which ultimately leads to higher possible scores. I have found that trickling the first few grains of the powder charge into the barrel before upending the measure to dump the bulk always fills the chamber and I have powder grains showing at the touch hole. a bump of the breech guarantees it. If the powder charge is dumped in bulk into the barrel it arrives at the breech in mass and cannot enter the breech chamber because of the bulk..

 

[Britsmoothy]

I wonder if the original poster is swabbing between shots or after a string of shots?

 

[Britsmoothy]

Sorry Treestalker. I wasn't trying to be clever.
Never had this happen myself but what with the issues suspiciously associated with swabbing I wondered if a damp crud ring was being developed during the shooting session.

 

[Grenadier1758]

It is easy to have a build up of fouling that can be pushed into the hole bored in the Pedersoli breech plug to form a fouling bridge or dam. The hole in the Pedersoli breech plug leading to the flash channel is about 5/16" or 8mm in diameter (0.312" to 0.323"). With a damp patch and wiping between shots, it is easy to fill that opening with fouling or be damp enough for the fresh powder to collect at the opening and not pass through to the flash channel.

There's several procedures to address the fouling build up or the collection of powder at the breech plug.

1. The easiest for those who wipe between shots is to use a thin wiping patch that slides over the fouling to bunch up and pull the fouling out. Then use 4fg or Null B fine powder in the pan and poke a few grains through the touch hole. Not enough to fill the touch hole and make a fuse, but enough to accelerate the ignition in the powder chamber. Use 3fg as the powder charge. The finer grains than 2fg will flow easier into the breech chamber and toward the touch hole.

2. Wipe with a damp patch and blow some compressed air through the touch hole to dry the flash channel and the breech chamber. Really too complicated.

3. Remove the breech plug and crown the entry to the breech chamber to create a funnel at the breech plug to the flash channel. There's less places for fouling to build up. You could also open the hole in the breech plug to 7/16" and crown the face of the breech plug. Be careful not to take more metal away from the breech plug face as you need the breech plug to mate fully on the threads in the barrel.

4. Don't wipe between shots. At least don't wipe to push fouling toward the breech. Use a slightly damp patch on the ball and a wet patch on the jag. The damp patched ball will slide over the fouling pushing some fouling on top of the powder and the wet patch on the jag will pick up fouling and remove it above the ball when the jag is removed. You will keep a consistent state of fouling in the barrel as you are wiping the barrel with the wet patch. The patched ball keeps excess moisture from getting to the powder.

5. Be aware that when shooting in conditions of high humidity, the fouling left in the barrel will be drawing water from the air and making the breech wet. That likelihood has to be kept in consideration if hand fires are starting to be experienced and a cleaning and drying of the breech and flash channel is necessary. A thin pipe cleaner or dental flossing brush will help to clear the flash channel.

 

[Sparkitoff]

Get a long, hard plastic tube ( I use one that a ram-rod came in). You could use a fancy brass "drop-tube". Push it down until it stops and pour in the powder slowly. Always gets into the PB unless there is a literal obstruction.

 

[Siringo]

I just picked up a used Pedersoli Trade Gun. Upon inspection using a bore camera on my IPhone I could see the breech face was fouled, but had a small hole in it. I was unaware that "P" put a patent breech on this flintlock. I knew they did on other percussion rifles as I had a couple. The previous owner must have had ignition issues. The vent liner has been changed and modified (see picture) and the powder pan has been beveled at the barrel mating surface to allow the powder to sit lower below the touch hole.

I think if the previous owner had ignition issues it was because of a fouled breech. I used a scraper and got a considerable amount of grayish powder out. The fouling was about 1/8 inch thick. Using a 22 caliber bore brush I got the breech hole cleared. I removed the barrel from the stock and gave it a good pumping of hot water/dawn soap flush. Camera inspection shows a clear hole now. My previous problems with patent breeches were swabbing between shots which forced fired debris into the flash hole. I will now only swab after loading with a patent breech.

 

[jcs266]

I'm reading this and (new guy here!) am wondering what is a Patent Breech? I envision a ML rifle as a straight tube with a vent hole where the nipple/cap or pan/vent send the flame through to ignite the powder charge behind the ball. Is this not correct? Where is this air gap occurring i guess is what's got me confused.

Thanks for the informative discussions here on the forum

 

[Britsmoothy]

I'm reading this and (new guy here!) am wondering what is a Patent Breech? I envision a ML rifle as a straight tube with a vent hole where the nipple/cap or pan/vent send the flame through to ignite the powder charge behind the ball. Is this not correct? Where is this air gap occurring i guess is what's got me confused.

Thanks for the informative discussions here on the forum

Someone smarter than me will get a diagram. Its basically a reduced diameter chamber in the breach plug.

 

[jcs266]

Thanks Britsmoothy i'm curious about it. I've never had a bore camera to look that far down, just a flashlight down the muzzle but it's not a detailed view. My rifles are both percussion Pedersoli's - wondering if they all have that breach design.

 

[Fly103]

Lots of good comments here guys, I use either mr flintlock lube or just spit on the patch when reloading. I dont swab between shots unless the fouling is causing loading issues. If i do swab i alsovsent a brass brush into breech to clear it.

I think alot of it is the buildup of crud on the breech face becoming damp with humidity and causing the powder to stick there rather than enter the breech chamber. As long as I pick the vent though i dont notice any delay in ignition so there isnt a large ammount of gunk buildup keeping the flash from traveling thru the breech to the powder.

Any idea what the capacity of the breech chamber is? I marked my range rod and there is only about 1/16" inch difference in ball depth with the chamber full vs empty.

Chris

 

[geco16ga]

The purpose of this design was to create an anti-chamber which would self- load with powder during loading. The ignition of the small powder charge created a jet of flame thru the small connecting hole into the main powder charge and was supposed to provide increased velocity and less fouling.

This is Henry Nock's design, there have been quite a few others since. This was during the peak of the bp era in the 1800s. These people knew what they were doing and had a lot riding on their designs.

 

[Grenadier1758]

Note the crowning in the Nock design to funnel the powder into the flash channel. That's an extra manufacturing step that is often neglected in modern chambered breeches. Sharp corners tend to collect fouling and build fouling bridges and dams to block the powder from reaching the flash channel.

 

[jcs266]

geco16ga,

Apic is worth a thousand words as they say - that’s very interesting thank you. I can fully see how that smaller chamber would propel the burn up into the center of the powder charge and accelerate the entire process.

 

[Zonie]

Nock's breech did improve the things mentioned by Grenadier and he Patented it.
Manton wanted to use the idea but he didn't want to pay Nock for the right's to use his Patented breech design so, he came up with the "chambered breech".
The chambered breech is easy to make which explains why almost all of the Italian made muzzleloading rifles on the market use it.
People call the Manton breech a Patented breech today but that isn't really correct. Manton did not patent his design.

I see this picture appearing all over the Google photo page but I have no fear of violating any copyrights. I am the guy who drew it.

 

[ohio ramrod]

Fly 103, Just wondering,where do you find an indoor range that lets you shoot black powder?

 

[jcs266]

Zonie,

Great diagrams - well done Sir! I think the Chambered Breach is what my Pedersoli has. I can see that “shoulder” down there at the edges and the deeper chamber centered behind it.