The “chamber” area of a muzzleloader...

[John Spartan]

Specifically the back end of the bore. How is it shaped?
Flat wall in the very rear? Cupped by design? Don’t really matter?
Talking a Perdersoli smoothbore in this case.

 

[Brokennock]

Specifically the back end of the bore. How is it shaped?
Flat wall in the very rear? Cupped by design? Don’t really matter?
Talking a Perdersoli smoothbore in this case.

You mean the breach face?

Flat is standard. Some are cupped slightly. Then, there is the controversial problem child,,, "chambered" or "patent" breaches. Whatever one calls then, I find them a nuisance. Controversial because a few people are not bothered by them, the rest of us range from annoyed by them to hating them.
These have a small diameter hole or chamber extending into the breach plug, the flash hole connects to this chamber instead of directly through the barrel wall into the main charge. Not a problem, until they get dirty, any number of things can cause them to foul sooner than one would like, and it generally can't be cleared with the tools commonly carried in the field.

 

[John Spartan]

Thanks.
Originally I was thinking of cleaning then wondered if “burn efficiency” was somehow figured in the shape.

 

[dave951]

I really hate a patent breech and especially those in modern guns like a TC. They can foul out and are a major PITA to get clean. I much prefer a flat breech face like on my muskets.

 

[Steve Martin]

dave951 said it brother, amen to that! The only flinter I owned that had a patent breech I finally sold for just that reason.

 

[Phil Coffins]

The chambered breech was invented for a reason, to judge the design based on mass produced and often cheap guns is short sighted.

 

[windini]

The chambered breech was invented for a reason, to judge the design based on mass produced and often cheap guns is short sighted.

Can you enlighten me as to what that reason is? Not trolling - I'm still new to muzzloading long guns and really don't know the engineering behind it.

 

[Brokennock]

The chambered breech was invented for a reason, to judge the design based on mass produced and often cheap guns is short sighted.

Lots if things have been, "invented for a reason," doesn't mean they are all good,,, or even really necessary,,, and especially doesn't mean they automatically deserve universal appreciation and praise.

 

[Phil Coffins]

Here’s what a well made chambered breech should look like, as apposed to what is found in some modern made guns.
https://www.trackofthewolf.com/Categories/PartDetail.aspx/304/1/PLAN-NOCK

 

[TreeMan]

I have half a dozen guns with a patent breech. Never had a problem with any of them. I don’t do anything different with those than any other gun as far as when loading or cleaning. The problems people speak of are exaggerated in my opinion. A bad experience with one gun does not constitute shaming all of those of the same design.

 

[Grenadier1758]

If you know you have a chambered breech, then you must use a loading and shooting procedure that is compatible with keeping a gun with a chambered breech reliably firing. First off there is little benefit to using a wet patch to wipe the bore while shooting as that will push wet fouling into the chambered breech. Dry patches on a standard jag can't remove the fouling that can't be reached. That will require a chambered sized brush and patch to reach in there to dry the chamber and use of a cap to blow fouling out of the touch hole.

The other process is to avoid wiping relying on the ball with its damp patch to keep the fouling constant in the barrel.

You will need to develop a process that works for your rifle.

 

[hanshi]

I've owned several guns with "patent breeches" and still have one that's a favorite of mine. Never have I ever had a problem with any gun traceable to that type of breech. They admittedly did all work fine for me. But, I just don't like them and have no particular reason; I just don't like them. I much prefer flat breeches and consider "patent" ones a solution looking for a problem.

 

[Coinneach]

Specifically the back end of the bore. How is it shaped?
Flat wall in the very rear? Cupped by design? Don’t really matter?
Talking a Perdersoli smoothbore in this case.

I cup all my Breech plug faces myself, only to around a 5mm depth and have to say its made a positive difference in ignition time; and yes I only buy quality Locks and tune them myself.

Current cupped Breech plug (BP) yet to be polished out, for my .50 cal swaged barrel, the concave depth of the BP is 5mm.

 

[John Spartan]

Nice!

 

[akroguy]

Not a fan of the sub caliber breeches. I get powder bridging in the .50 Pedersoli Kentucky flinter and, to a lesser extent, the .54 GPR caplock. I shoot 2F (as I have a lot of it) so maybe smaller granule 3F would fix that. It just seems an unnecessary nuisance. My Zouave and '61 Springfield just go bang every time without fail. The breeched guns are about impossible to get really clean. Pulling the breeches and milling out to a larger diameter with a chamfered shoulder is a "to do" list item for these.

 

[William Lincoln]

The idea of the Patented breech was to improve the burn of the charge
and direct it--or attempt to.

 

[GoodRabbitPilgrim]

I have multiple patent breech pedersoli guns, clean them properly and you will have no issues. I would not part with mine. Q