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General discussion => Black Powder Shooting => Topic started by: ClaudeH on December 14, 2018, 09:18:04 PM

Title: Breech plug removal
Post by: ClaudeH on December 14, 2018, 09:18:04 PM
The thread on vent liners led me to ask:

Doesn't conventional wisdom say that breech plugs should not be removed from the import/factory guns?

I'd like to remove and inspect the plugs on my Investarms and Pedersoli guns but I've been told not to ty it.

Of course, being patent breeches, there would still be problems determining the length for trimming the protrusion of a vent liner.

Title: Re: Breech plug removal
Post by: stikshooter on December 14, 2018, 10:24:07 PM
Use search at top right I believe (RFD ) Rob explained this topic very well /Ed
Title: Re: Breech plug removal
Post by: Flint62Smoothie on December 15, 2018, 12:09:47 AM
I'd like to remove and inspect the plugs on my Investarms and Pedersoli guns but I've been told not to ty it.
Not broken ... don’t fix it. I too would never attempt on any of the foreign builds.
Title: Re: Breech plug removal
Post by: EC121 on December 15, 2018, 01:03:31 AM
There is a small camera sold online that hooks to a laptop or phone.  It can go in the muzzle for a look a lot easier.
Title: Re: Breech plug removal
Post by: Flint62Smoothie on December 15, 2018, 07:21:45 AM
There is a small camera sold online that hooks to a laptop or phone.  It can go in the muzzle for a look a lot easier.
GREAT idea! Lookiehere for the amazing photos taken w/ a $14 LED endoscope!

http://americanlongrifles.org/forum/index.php?topic=37808.msg363398#msg363398
Title: Re: Breech plug removal
Post by: ClaudeH on December 15, 2018, 07:41:49 AM
Use search at top right I believe (RFD ) Rob explained this topic very well /Ed

Thanks for pointing me towards RFD's posts.  He spoke with more specificity than I remembered.  I found this posting:

"i wouldn't install any new touch hole liner without first removing the breech plug, IF the breech plug can be removed. 

this has never been a problem for me with a traditional breech plug - i use a rice breech wrench and rice octo vise plates. 

this CAN be a real problem for most of those production patent breeches, like traditions and cva (they are practically welded on and the manufacturers advise that attempting to remove will bugger the barrel), and add in pedersoli.  investarms (lyman, dgw and the like) can be removed with a good flat jawed wrench (reed rcorp) and a heavy bench vise."

Also:

"now here's the other problem with most offshore trad ml rifles - removing their patent breech plugs IF and WHEN that chore needs doing.  this is a "can do" with investarms guns, a "maybe" with pedersoli guns, and a big "no no" with all the spanish guns (traditions and cva).  but maybe there'll never ever be a need to pull that breech plug.  hopefully."

It looks like my Investarms breech plugs can be removed and replaced but my Pedersoli is a $#@* shoot?

I know I'm beating a dead horse, but I wish someone could relate more specific, experiential information on removing and replacing the patent breech plugs on the other imports.  What sort of damage occurs from removing them?  What does it take to repair the damage and re-breech the barrel?

There ought to be nomenclature to differentiate the two types of patent breeches:  The ones that ignite through both the wall of the barrel and the wall of the ante-chamber of the breech plug versus the ones that ignite directly into the ante-chamber.

Whatever you call them, the modern European factory Patent breeches that ignite through the barrel and then through the breech plug wall seem to be an abomination.  The ante-chamber is incredibly narrow and deep, causing ignition dificulties.  It seems like there is room for improvement of these plugs and I'd love to hear of anyone's results in improving them. 


Title: Re: Breech plug removal
Post by: ClaudeH on December 15, 2018, 07:46:15 AM
There is a small camera sold online that hooks to a laptop or phone.  It can go in the muzzle for a look a lot easier.

I have one.  It is narrow enough to slide down the .223" barrel of an unmentionable.  But it will not enter the absurdly narrow ante-chamber of my patent breech!
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 03:48:56 AM
i've worked on quite a few (as in more than a few dozen) offshore patent breeches. 

i've never been able to remove a new ("new" as in bought brandy new, not owner fired) spanish gun's patent breech - maybe it was just the luck of the draw, i dunno nor do care for those guns anyway. 

the few new pedersoli guns were just like the spanish guns and those plugs appeared to be welded on.  now i like pedersoli guns in general, in particular their bpcrs, and i dunno why i couldn't budge those plugs - again, might just have been *those* guns. 

with all the new investarms (rebranded as lyman, cabela, dgw and others) i had no problem with plug removal. 

trying to remove a breech plug from any used barrel, whether offshore patent or onshore classic flat, might be a chore even with the right barrel brand and the right tools IF the threads weren't initially properly greased or teflon taped, because it's a guarantee that bp residue will eventually mitigate anything threaded anywhere into a barrel.

why do i want to remove a new gun's breech plug?  to "nikal" anti-seize grease, for possible future removal or replacement.  does everyone need to do this?  of course not.  i do this greasing as well with any touch hole liner.

for all the above offshore guns i use an 18" reed corp wrench stuck into 36" length of black iron pipe, and a specialized offshore gun wrench "socket".  these tools make the job relatively easy, but one could use a pipe wrench and deal with some plug buggering.  for onshore classic flat faced breech plugs i use a rice barrel socket wrench slipped into a 42" length of black iron pipe for leverage.  for vising the barrel i use rice octagonal vise barrel clamps.
 
hope this helps! 
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 04:02:55 AM
to confirm, again, there is really no need to remove a patent breech - but there are some things to be aware of .... 

by its design, the patent breech can't be swapped out for a standard flat breech - the two are radically different. 

the patent breech has a "flue" or "ante-chamber" that's set back from the real ignition chamber and that flue is a much smaller diameter that the barrel's bore.  therefore, when you patch jag clean these barrels, yer just gonna push crud into that ante-chamber.  once the barrel is cleaned out, a .22 to .32 wire brush that's draped with a wet patch can get down into the patent breech and clean it out.  it must be dried, too!

be aware that there is minimum amount of powder charge to use, because while the powder charge will pour down into both the patent breech and the barrel, the patched ball won't - it's stopped by the ante-chamber's mouth.  a typical ante-chamber needs about 15 to 30 grains to fill it.  if you don't fill it, and use a really light charge, there could be an air space between that charge and the patched ball.  this is NOT a good black powder load condition.

yeah, lots more to do with a patent breech than a classic flat breech, so why have them in the first place?  the design thinking is that a patent breech allows for faster and more consistent ignition.  personally, i don't find that true at all, and the added work is actually a detriment for me.  but the market is flooded with offshore sidelock muzzleloaders that are far Far cheaper than an onshore custom gun, and that's what some folks, newbies and old timers alike, will buy.  all depends on wants and needs and bank accounts.
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 04:04:58 AM
a lyman GPR and a pedersoli patent breech ...

(https://i.ibb.co/z7HFtZn/ante-chamber.jpg) (https://ibb.co/cCXwsQg)
Title: Re: Breech plug removal
Post by: Turtle on December 16, 2018, 07:19:35 PM
 on foreign Some touchhole liners and caplock vents lock into the breachplug. If you try removing the breechplug without first removing them you wreck things---I found that out the hard way. TC breechplugs are super tight. I ended up buying a special breechplug wrench for hawkens and senecas. Make a shaped breech scraper that fits in your pre chamber to clean it.
Title: Re: Breech plug removal
Post by: OldMtnMan on December 16, 2018, 08:25:14 PM
I've posted this before but if you missed it. Here it is again. It's great for the patented breech. Stiff bronze bristles. It will size itself to the hole. The extra ones not needed to fill the hole will bend back. Then turn the ramrod as you push in. That will spread the bristles in the hole. Do it first while the fouling is dry. Then flush out with the bore flushing.

http://www.octobercountry.com/msm-breech-brush/
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 08:33:40 PM
on foreign Some touchhole liners and caplock vents lock into the breachplug. If you try removing the breechplug without first removing them you wreck things---I found that out the hard way. ...

yep, as in the pedersoli frontier diagram i posted above, where the touch hole liner needs to come out before unscrewing the breech,
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 08:39:00 PM
I've posted this before but if you missed it. Here it is again. It's great for the patented breech. Stiff bronze bristles. It will size itself to the hole. The extra ones not needed to fill the hole will bend back. Then turn the ramrod as you push in. That will spread the bristles in the hole. Do it first while the fouling is dry. Then flush out with the bore flushing.

http://www.octobercountry.com/msm-breech-brush/

that'll work ok for most of the offshore .50 and above bores with .336" breech flues, but not the small bores that'll have breech flues of .300" and under.

the brush is more of a scraper and doesn't address the entire flue - been there, done that.  in the long run the flue is best handled with a standard appropriate size bronze bore cleaning bristle brush, with and without a draped-on patch.

in any event, this is why patent breeches really benefit from constant and immediate attention from whence they get dirtied with bp residue.
Title: Re: Breech plug removal
Post by: OldMtnMan on December 16, 2018, 09:25:29 PM
It will self fit. When you push it in the hole the unwanted bristles will bend back. Then when you remove it from the bore you can cut off the unwanted bristles.

I'm not sure how you get a brush in the channel? You'll have to explain that to me. I usually use special pipe cleaners through the clean out hole. The pipe cleaners have small wire bristles sticking out. Sort of made to clean guns.  I got them from Brownells.
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 09:45:12 PM
firstly, i'm talking about an offshore patent breech plug.  none of this cares much about the type of ignition system, flint or cap.  the flue or ante-chamber is smaller than the bore, a lot smaller.  for a typical .50 or .54 bore the flue is .336 - measured on a lyman GPR.  i use a .30 caliber bronze brush draped with a 2" arsenal patch to get into the chamber and swap out the bp residue.  this is done after the barrel has set some minutes with the touch hole (flint gun) plugged with a toothpick and tepid tap water down the tube.  drain the water out the touch hole and run a patched jag down the bore using moose milk, til the patches come out reasonably clean.  forcing that fluid out the touch hole agitates the cra@p in the anti-chamber.  now a run the .30 patched bronze brush in the chamber and swab it out.  plain water to rinse all, dry patches for tube and ante-chamber, last patch is lightly oiled.  done.

having used that other brush, it will never get into a chamber of a gun much less than a .50 because its shank is also about .30 and smaller flues are less than .300 in diameter.  been there, done that.  there is a huge difference 'tween that october msm straight brush and a typical bore twisted bronze or nylon brush, the later i believe is superior.  that some, if any, of the forward bristles on an msm brush with bend back as they're restricted by the narrower flue, isn't gonna be as good as a standard spiraled bristled bore cleaning brush.  ymmv.
Title: Re: Breech plug removal
Post by: OldMtnMan on December 16, 2018, 10:32:14 PM
The brush I showed is a better idea than a scraper.  I thought that's what we were talking about? Used like that it will fit any size hole. I use it on a GPR.
Title: Re: Breech plug removal
Post by: rfd on December 16, 2018, 11:03:26 PM
the brush is better than nothing, but if you have baked on bp residue from negligence, then a real scraper is what's required.

the tools and materials required for bp cleaning all depend on how well a barrel/gun is maintained.

Title: Re: Breech plug removal
Post by: OldMtnMan on December 17, 2018, 01:27:05 AM
Not interested in arguing about it. I was just trying to help.
Title: Re: Breech plug removal
Post by: rfd on December 17, 2018, 01:31:49 AM
there is no argument, there's only what each of us feel like doing. 

and it's always good if good stuff happens.
Title: Re: Breech plug removal
Post by: ClaudeH on December 17, 2018, 06:49:43 AM
rfd,  Thanks for taking the time to share so much about these modern patent breeches.

These things irk me.  I know part of it is my tenderfoot status and I will learn to manage them better, but they seem like an abomination of design.  I cannot comprehend how a .220" slender and deep ante-chamber is anything but an impediment to reliable ignition.  I cannot comprehend why the walls of the plug need to be that thick when the plug is surrounded by a barrel that would be considered strong enough in and of itself with a conventional breech plug.

When I have seen the patent drawing of Nock's patent breech it has a hemi-spherical lead-in and a relatively short ante-chamber.  But my Italian versions have a totally flat face perpendicular to the barrel wall and it is a big, broad flat face better designed to facilitate bridging of the powder charge and exclusion from the ante-chamber rather than facilitating getting the charge down to the vent.

Inasmuch as my Investarms and Pedersoli were obtained used, it seems like trying to remove the plugs is ill-advised.  Is there any trick to getting a replacement touchhole liner to fit properly flush with the interior of the ante-chamber?  I guess it is inevitably a cut and try process that is facilitated by a bore scope.

I'd like to experiment with improving these plugs, but it will have to wait until I have a budget to acquire some junk barrels.  It seems like they could be improved by widening or tapering the ante-chamber and radiusing the entrance to the ante-chamber.  I wonder if anyone has experimented with this and has results to relate?

If I can pester you just a bit more, rfd:  When do you use the hex sockets versus the Reed rcorp wrench?  Is the Rice breech plug wrench always the superior choice for conventional plugs?  (Thanks!)
Title: Re: Breech plug removal
Post by: rfd on December 17, 2018, 03:34:12 PM
rfd,  Thanks for taking the time to share so much about these modern patent breeches.

These things irk me.  I know part of it is my tenderfoot status and I will learn to manage them better, but they seem like an abomination of design.  I cannot comprehend how a .220" slender and deep ante-chamber is anything but an impediment to reliable ignition. 

actually, the intent of the patent breech is to insure that the powder charge ignites from its base.  some, if not a lot of flat faced breech plugs will have a trough or channel cut into their face that point directly back at the touch hole - again, to insure ignition from the base of the powder column.

(https://i.imgur.com/3a4dG38.jpg)

I cannot comprehend why the walls of the plug need to be that thick when the plug is surrounded by a barrel that would be considered strong enough in and of itself with a conventional breech plug.

ignition chambers need to be strong, particularly where threads are involved.

When I have seen the patent drawing of Nock's patent breech it has a hemi-spherical lead-in and a relatively short ante-chamber.  But my Italian versions have a totally flat face perpendicular to the barrel wall and it is a big, broad flat face better designed to facilitate bridging of the powder charge and exclusion from the ante-chamber rather than facilitating getting the charge down to the vent.

for the most part, i've found the offshore patent breeches work just fine for their design.  that's not the issue, it's about addressing fouling control and cleaning that can be more of a pain than a classic flat faced breech plug.

Inasmuch as my Investarms and Pedersoli were obtained used, it seems like trying to remove the plugs is ill-advised. 

not necessarily.  i've removed quite a few investarms breech plugs that were years old and never properly greased.  it's the luck of the draw sometimes.

Is there any trick to getting a replacement touchhole liner to fit properly flush with the interior of the ante-chamber?  I guess it is inevitably a cut and try process that is facilitated by a bore scope.

measure, cut and try and see and "feel' with a patched jag.

I'd like to experiment with improving these plugs, but it will have to wait until I have a budget to acquire some junk barrels.  It seems like they could be improved by widening or tapering the ante-chamber and radiusing the entrance to the ante-chamber. 

depends on how the patent breech is designed and built.  i think you'll find that most if not all will be limited by their threads and the barrel's threads.

I wonder if anyone has experimented with this and has results to relate?

it would surprise me if there were any positive results.

If I can pester you just a bit more, rfd:  When do you use the hex sockets versus the Reed rcorp wrench?  Is the Rice breech plug wrench always the superior choice for conventional plugs?  (Thanks!)

the reed corp flat jawed wrench is used in concert with the patent breech plug hex socket.  this insures the breech won't get buggered as it will by just using a wrench.  the rice barrel wrench works only for classic non-patent breech plugs, or any breech plug that has a goodly tang for socket purchase.


hope some of this helps ya.
Title: Re: Breech plug removal
Post by: bob in the woods on December 17, 2018, 04:33:34 PM
Back to the original question. How do I remove these patent breeches ?   With a hacksaw.  Good riddance  :)
Title: Re: Breech plug removal
Post by: Turtle on December 17, 2018, 05:06:18 PM
 OK the original question. On TCs I use a tool that fits over the breech to provide something to get a BIG wrench on without damageing the breech plug---one could be made for others or a TC wrench modified.  I clamp the barrel in a BIG vise with hex barrel blocks from Brownells and grunt.  We used to sell a brass scraper with a curved bottom in the size of some prechambers. The Pedrosolli Mortimer had the smallest chamber--- 54 cal and app 1/4" chamber as I recall..
Title: Re: Breech plug removal
Post by: rfd on December 17, 2018, 05:15:14 PM
Back to the original question. How do I remove these patent breeches ?   With a hacksaw.  Good riddance  :)
\

dangit, yer so dingy dang dong clever!!!  :o  ;D
Title: Re: Breech plug removal
Post by: Bob Roller on December 17, 2018, 05:29:04 PM
Back to the original question. How do I remove these patent breeches ?   With a hacksaw.  Good riddance  :)

I still have a TC breech plug removed with a saw.The barrel
was made into a couple of pipe tomahawks.
I have a heavy 5" vise on the end of my bench and a friend
who was 6'8" and nearly 400  pounds couldn't move that plug
so the horizontal bandsaw got the job.

Bob Roller
Title: Re: Breech plug removal
Post by: rfd on December 17, 2018, 05:43:26 PM
ah, the amazing welding power of bp mitigation into breech plug threads! 

and some folks poo-poo the concept of greasing new plugs and having obsessive post-shoot barrel cleaning regimens.

Title: Re: Breech plug removal
Post by: ClaudeH on December 17, 2018, 08:19:11 PM
Thank you, rfd, for useful information and feeding my curiosity.

Where do you obtain the hex sockets?  I take it they must be a little different from one I might use with a breaker bar, since they need a surface for the wrench to get a purchase.

I thought a picture in one of your past posts showed the rcorp wrench on the hook of a breech plug.  If that was the wrong impression, I'm glad you provided more information before I messed up a rifle.

I kind of dread taking massive force to my two Investarms/Cabelas Hawkens' because their 15/16", .58 caliber barrels are kind of scarce and I'd hate to bugger them up.  But I would like to have the plug threads clean and properly preserved and feed my curiosity by a closer inspection of the plugs. 
Title: Re: Breech plug removal
Post by: rfd on December 17, 2018, 09:01:22 PM
this is a reed corp wrench and patent breech wrench (acquired off ebay, for 15/16" barrels) working together to remove a GPR patent breech ...

(https://i.ibb.co/Y8BLYNB/DSC01705.jpg) (https://ibb.co/bL5Kq65)

this is a rice barrel wrench, in concert with the leverage of an iron pipe, removing a standard breech plug ...

(https://i.ibb.co/w6gNDFP/DSC04479.jpg) (https://ibb.co/PCjZBvP)
Title: Re: Breech plug removal
Post by: Turtle on December 18, 2018, 12:31:47 AM
 The tough ones I got out weren't seized due to corrosion, they were just stinkin tight!
Title: Re: Breech plug removal
Post by: rfd on December 18, 2018, 12:45:18 AM
The tough ones I got out weren't seized due to corrosion, they were just stinkin tight!

i believe those kinda plugs were designed never to be removed.  according to the traditions manufacturer, attempting to remove a plug would destroy the barrel itself.  i read that in one of their trad ml "manuals". 
Title: Re: Breech plug removal
Post by: Turtle on December 18, 2018, 01:52:20 PM
putting them in so tight may be due to liability concerns
Title: Re: Breech plug removal
Post by: rfd on December 18, 2018, 03:03:51 PM
putting them in so tight may be due to liability concerns

to protect the stupid at the cost of the smart.  seems to be the way most things go, these dayze.
Title: Re: Breech plug removal
Post by: cantom on February 13, 2023, 10:13:39 PM
Hello to RFD and anyone else who knows!

I just bought a Jonathon Browning Mountain Rifle in .45. It's in beauty shape.

I'm wondering what make, shape or taper of jag/brush/scraper I need to clean right down to the bottom of the breech plug.

I was going to ask if I should remove the plug so I can Never Seize the threads, but...I found a thread elsewhere that said to never ever remove this plug on these rifles as they are torqued plus silver soldered in place.

Comments and knowledge much appreciated.
Title: Re: Breech plug removal
Post by: Daryl on February 14, 2023, 12:51:53 AM
Cantom, I suggest you buy a .45 cal. jag from Track with the proper thread (8x32 or 10x32) to fit your rod or loading cleaning rod. I suggest you size (file) the jag to allow a snug
fit of 2 layers of cotton flannelette for cleaning patches. This will easily get to the bottom of the grooves for cleaning.
You can use the search engine here at ALR to find threads with cleaning regimes for cleaning with easily removable barrels.
Title: Re: Breech plug removal
Post by: cantom on February 14, 2023, 01:37:52 AM
Yes indeed, but I'm referring to what they were talking about in this thread, the bottom of the patent breech shape in the breech plug. Since you can't see it, what kind of crud is building up in there?
A poster elsewhere in internet land referred to the need on the JBMR for a jag that tapers at the front so it can reach down into that recess.

Someone said people have had regular squared off jags actually stick down there, getting stuck in the taper.

The gent I bought the rifle from said he had a gent make him a custom scraper at one time, but apparently it didn't work so well. Imagine if you had the breech plug out and make one to scrape and fit precisely.

Thus my desire to be able to remove the breech plug at will to be able to ensure down there is cleaned out well.

With regard to the easily removed breech plugs on the current crop of inline muzzle loaders...how lucky they are.
Title: Re: Breech plug removal
Post by: cantom on February 14, 2023, 01:39:21 AM
ah, the amazing welding power of bp mitigation into breech plug threads! 

and some folks poo-poo the concept of greasing new plugs and having obsessive post-shoot barrel cleaning regimens.

Yes!
Title: Re: Breech plug removal
Post by: smylee grouch on February 14, 2023, 02:14:52 AM
Forget about a jag to clean the ante-chamber in the breech plug, get a slotted tip for your cleaning rod and use a flannel patch on it to get down in that small hole. Use room temp water in a flushing action in and out to clean the barrel and you will flush all the crud out. Dry with two or three clean dry flannel patches and then use a good dose of WD 40 and patch out the excess.
Title: Re: Breech plug removal
Post by: cantom on February 14, 2023, 02:59:25 AM
I have partially come up with a solution. I've just scored 2 pounds of American Pioneer powder. Cop out I know.

Very interested in what rfd has to say too or anyone who's actually seen a JBMR with breech plug out. I do love the idea of being able to Never Seize the plug.

But, if it's silver soldered in...

Quote
These are a very solid rifle. One interesting aspect of the gun is that the breech plug is threaded and silver soldered in place. Don't even think about removing that breech plug.
Title: Re: Breech plug removal
Post by: cantom on February 14, 2023, 03:00:13 AM
Forget about a jag to clean the ante-chamber in the breech plug, get a slotted tip for your cleaning rod and use a flannel patch on it to get down in that small hole. Use room temp water in a flushing action in and out to clean the barrel and you will flush all the crud out. Dry with two or three clean dry flannel patches and then use a good dose of WD 40 and patch out the excess.

Okay, yes, I'll do that and thanks.
Title: Re: Breech plug removal
Post by: smylee grouch on February 14, 2023, 04:21:49 AM
I think there are many on this forum that will tell you that you will do more harm to your gun with that powder as you would removing the breech. JMHO
Title: Re: Breech plug removal
Post by: Dphariss on February 14, 2023, 05:39:46 AM
The thread on vent liners led me to ask:

Doesn't conventional wisdom say that breech plugs should not be removed from the import/factory guns?

I'd like to remove and inspect the plugs on my Investarms and Pedersoli guns but I've been told not to ty it.

Of course, being patent breeches, there would still be problems determining the length for trimming the protrusion of a vent liner.

I would not. Its possible, depending on how it was installed that when you reinstall it might turn past index. IE be loose at the index point.
In reference to Bob Roller’’s TC “experience” some were known to break off  when removal was attempted since they were machine installed and would over stress the rebate at the breech end of the threads and they would break at that point.
I have had one factory made in the shop over the years, Browning Mtn Rifle. Very poorly breeched. Significant gap for fouling trap. But you will find this or worse on some barrels made here in the USA. I won’t go any farther with this less I get in trouble. All I will say is I don’t order barrels with breeches installed a friend sent me one to stock and I spent over an hour on the lathe getting it refit so the makers name was in the same relation to the patent breech. I pulled it to make sure it was right and it wasn’t. So the name on the barrel does no
Title: Re: Breech plug removal
Post by: Dphariss on February 14, 2023, 05:44:32 AM
American Pioneer powder. IIRC is basically useless. I would have to did back into my Mad Monk archive but like all of them they are remakes or modifications of powder tried in the 19th c and they were useless then too.
One of these was so hygroscopic, That a horn filled with it hung on a wall started to drip liquid. But again I would have to dig to get the exact name. Others produced wild variations in velocity, either because of the basic powder or because they suck up water from the air. One at least, is wildly corrosive.
Title: Re: Breech plug removal
Post by: taterbug on February 14, 2023, 08:00:52 PM
one of the suggestions in that original thread, was to purchase, and use, a small inexpensive camera (endoscope) attached to a cell phone.  These are still available. 

If you are so worried about the breech on this gun, I would think a camera for less than $20 might be a good alternative to ruining what may be a perfectly functional gun.  It would also help ease your concern about cleaning the gun after shooting.