Chasb 

Nope.  Not do-able.  With PLUS ONE for Cap'n Redneck.  A re-chamber as you describe would be extremely thin and would "shoot out" rather quickly.  Nope. can't do that.

A chamber can be re-done, repaired, etc., but has to be done with a liner, where the hold chamber is machined out and a new chamber, appropriately THICK, is machined and inserted.  this leaves the original barrel intact.  Or cut the barrel, set it back and cut a new chamber.  There is no "quick and easy."

  Doc 
Ah well.  NONE of the above.  I know your OP inquired of Black Powder, but I'd be directing your attention to APP and/or Shooters World Black.  Both are excellent Substitutes, are easy to clean-up and require NO lubricants.  That's right, NO lubricants and you can shoot coated bullets all day.  The barrel fouling from APP is also not cumulative.  Each shot cleans out the previous fouling.  Reducing the charge is done with simple fillers (I like Cream-0-Wheat).

I have shot with my close shooting compadre who shot the 45-70 for Planesman.  His round was a reduced load and Round Ball.  Shot like a laser and rang steel just fine.  Just crimp the round ball at its equator and shoot away.  Just another option to muddy the waters.

  OK Jeremiah 

Been going on Seven Months now.  How about the results??  We have all been wondering how that hat turned out .. or didn't.

PSST:  HEY G C R - I really like that El Darado (Dorado) Hat.  Just add a set of goggles and some other accouterments and WOWZERS!!

The Captain had good advice. I will add, though, that at 50 yards, most trapdoor loads I have used require at least a 6 o'clock hold to not over shoot the target. At least that has been my experience with sass type targets-6 o'clock will get hits on the upper part of the steel as cas ranges. One option for powder measure is to go somewhere that has muzzle loader supplies and get an adjustable powder measure. Basically it's just a brass tube with an adjustable plug, and markings for the approximate grain weight.

Quote from: GunClick Rick on September 06, 2024, 03:44:44 PMEl Darado hat.

OR are you really a member of the Dickens Christmas Carol Club?

70 grains of 2f black powder, under a .030 fiber wad with a 405 grain bullet cast from either 20-1 or 16-1 alloy lubed with a good bp cartridge lube ( my preference is Bullshop Nasa) cases primed with a large rifle primer.

I fully support everything the good Capt told you.
Lighter loads with greased wads or filler is good, easy on the wallet and the shoulder.
I especially like the .458 or so roundball loads.

These days with powder prices what they are, stretching your powder dollar is only smart
For punching paper or ringing gongs.

Yhs
Prof marbles

Quote from: GunClick Rick on September 06, 2024, 03:06:24 PMI HAVE AN A. Uberti 44 mag with conversion cylinder..........

Greetings Rick!

Its been a long time you old scudder!

What the other guys said is dead on. Especially the two mikes.

We are all amused by your "Uberti .44 Mag bp revolver"
If I were a betting man, which I am not, I would bet a nickle that you are using a smart phone
with autocorrect and autofill? The blasted things keep sticking the wrong stuff in and one does not
always notice ....

Yhs
Prof marbles

When the two Mikes agree, it must be right!  Or a conspiracy the likes of which has rarely been seen!

The original TrapDoor carbine load was 55 grains blackpowder behind the 405 grain lead bullet.  The difference from the 70 grains infantry rifle load was taken up by wads.

I would suggest getting Swiss 1,5 Fg blackpowder if possible; it is the cleanest burning type that I know of.  "Olde Eynsford" (by Goex?) is a close second. 

You could start with 50 grains of blackpowder and work up or down in 5 grain increments from there.

Try Sesame-seeds as a filler between the powder column and the bullet.  Sesame-seeds contain up to 50% oils, and might be just the trick to get the amount of lubrication you need with the coated 300 grain bullets. There should be no need for wadding between the powder/sesame-seeds/bullet, but a milk-carton wad acting as a "gas check" under the bullet won't hurt.

With blackpowder the exact powder weight is not as critical as with smokeless.  You don't need a special powder dispenser.  You can make a scoop out of, say a .30-06 case; cut off the neck so it becomes a straight-wall case, twist a piece of bailing wire into a handle, fastening one end in the extractor groove and making the other end into a 4 inch handle.  Might have to secure it to the case with some solder or glue.
Then you just pour blackpowder into a bowl and scoop it up and pour it into your cases.  The scoop can be cut down with a hacksaw and filed to the required length for the amount of powder you deem optimal for your use.

At only 50 yards you could even try loading a .457" round ball for percussion revolvers in the .45-70 case... -it will definitely ring steel at that distance.
I believe I've seen pictures of original .45-70 cartridges with roundball loads that were termed "Forager rounds".

Clean-up is easily accomplished with luke-warm water and a little dish-washing detergent added.  You can also look for a spray-bottle of "Windex with vinegar" at your local K-Mart / Wal-Mart; it was the preferred blackpowder clean-up medium of the late Mike Venturino.  You should also drop the recently fired cases into a plastic jug with soapy water at the range, it will make clean-up easier when you come home.

Consider getting a plastic funnel, fitting about a 6 inch length of hose to it that will fit into the chamber of the TrapDoor carbine; that way you can flush most of the gunk out the muzzle before you start swabbing the bore.

If you are getting lubed bullets you can't go wrong with SPG blackpowder lube.