Im new here but this is a very good forum with tons of info.

I decide to begin an old project, that is to make and regulate a muzzleloader DR.
It must be muzzleloader because you have to be a registered gunsmith to make cartridge guns in Argentina but you have no problems with muzzleloaders.
An old gunmaker friend give me two .50” rifled barrels of his make some years.

My project is to make a double in-line muzzleloader on a double shotgun.
I plan to sleeve the barrels and put then in the monoblock. I will make the plug to accept a 209 primer as most in-line. This way I can use the gun as a standard DR but only loading it by the muzzle.
I ordered the book “Making double rifles on shotguns” and I will have it in a week.

I want to know if:
Is there any thread on a similar project?
Do anyone made a similar rifle?
I’m looking for advice.
Thank you very much!