Breech chamber question in a flintlock Fowler

[PathfinderNC]

I have a .69 caliber flintlock Fowler. Running a patch down the barrel I found that the patch and jag become quite loose at the breech, about three inches from the face of the breech plug.
The barrel was never used before ( it had no touch hole yet), so I am curious if this was a barrel design to have a slight taper from the breech area into the bore?

 

[rich pierce]

I have a .69 caliber flintlock Fowler. Running a patch down the barrel I found that the patch and jag become quite loose at the breech, about three inches from the face of the breech plug.
The barrel was never used before ( it had no touch hole yet), so I am curious if this was a barrel design to have a slight taper from the breech area into the bore?

No, this is not a design feature. And you could drop a patch easily using a jag if it’s loose enough. Using a worm instead of a jag is a good work-around. Otherwise, I’d accurately ream the barrel to a consistent bore diameter end to end. The only way I can do that accurately is to use a reamer, not a brake hone, or abrasives on a stick, or lapping. Adjustable reamers work well for me.

 

[PathfinderNC]

No, this is not a design feature. And you could drop a patch easily using a jag if it’s loose enough. Using a worm instead of a jag is a good work-around. Otherwise, I’d accurately ream the barrel to a consistent bore diameter end to end. The only way I can do that accurately is to use a reamer, not a brake hone, or abrasives on a stick, or lapping. Adjustable reamers work well for me.

Thanks Rich. Its a 51" barrel, so would this be a job for a professional?

 

[rich pierce]

Thanks Rich. Its a 51" barrel, so would this be a job for a professional?

If you’re comfortable with using a worm, it should be fine to use. Jags with thin patches are very sensitive to diameter. It may only be 0.001-0.003” wider at the breech. Another option is to clean with a smaller jag and doubled or tripled patches. I routinely do this. I use a .40 or .45 jag in a .50 and so on. .50 jag in a .58. The doubled and tripled patch soaks up a lot more fouling in each single pass.

 

[PathfinderNC]

If you’re comfortable with using a worm, it should be fine to use. Jags with thin patches are very sensitive to diameter. It may only be 0.001-0.003” wider at the breech. Another option is to clean with a smaller jag and doubled or tripled patches. I routinely do this. I use a .40 or .45 jag in a .50 and so on. .50 jag in a .58. The doubled and tripled patch soaks up a lot more fouling in each single pass.

One work-around I do is to file slimmer the cleaning jag with it in my drill press chuck. With a smaller jag I can use thicker cleaning patches like old cotton sweatpants that can compress and expand.
It seems odd that the breech chamber would be wider then the rest of the bore, though.

 

[Billy-by-gosh]

One work-around I do is to file slimmer the cleaning jag with it in my drill press chuck. With a smaller jag I can use thicker cleaning patches like old cotton sweatpants that can compress and expand.
It seems odd that the breech chamber would be wider then the rest of the bore, though.

A breech that's wider-than-bore sounds like a bit of a forcing cone design. If you can keep it clean, might be worthwhile to keep it to experiment with. You could always ream or lap to the larger diameter.

 

[PathfinderNC]

A breech that's wider-than-bore sounds like a bit of a forcing cone design. If you can keep it clean, might be worthwhile to keep it to experiment with. You could always ream or lap to the larger diameter.

I was wondering if it is a forcing cone, particularly since it was made as a fowler .

 

[Brokennock]

I don't see why one would need a forcing cone on a non-cartridge smoothbore gun.... But, I don't believe to know everything.

 

[PathfinderNC]

I don't see why one would need a forcing cone on a non-cartridge smoothbore gun.... But, I don't believe to know everything.

Evidently it was a thing in the old days.

 

[flconch53]

A breech that's wider-than-bore sounds like a bit of a forcing cone design. If you can keep it clean, might be worthwhile to keep it to experiment with. You could always ream or lap to the larger diameter.

It would take a lathe with alot of travel to ream your bore.

 

[Capt. Jas.]

Some original fowling guns had barrels with a relieved breech area as well relieved at the muzzle. These were early experiments to control shot patterns before choking was done. Many of the relieved breeches were also "roughened".
Is this a modern manufacture barrel? If so, could it be made from a shotgun barrel with a forcing cone?

 

[PathfinderNC]

Some original fowling guns had barrels with a relieved breech area as well relieved at the muzzle. These were early experiments to control shot patterns before choking was done. Many of the relieved breeches were also "roughened".
Is this a modern manufacture barrel? If so, could it be made from a shotgun barrel with a forcing cone?

@Capt. Jas. can you describe a bit what you mean “Many of the relieved breeches were also roughened”?
The inside at the breech of this barrel has some roughness in it that I can almost catch a tight patch on and I was wondering what it is about (like maybe threads?). The area is about one inch forward the face of the breech plug.
This barrel certainly looks like it was intended for muzzleloading (not a modern made shotgun barrel), and had no touch hole yet so it was unused. Inside is bright and gleaming shiny so any possibility of a rust ring is null.
Thanks for any info!

 

[PathfinderNC]

Here’s what the breech looks like using my bore scope. The protruding thing is a wire I inserted through the touch hole.
The visible ring reveals where the slightly narrower breech chamber opens to a wider bore.

 

[2 shots]

did someone over drill or bore for the breech plug??