With the talk of jb bore cleaner I thought I would ask a related question.

Picked up a trap door recently and bullets tumble when shooting. Slugged the bore and got .452 dia. No sign of rifling on the bullet I slugged the bore with. That doesn't make sense. So I figured the grooves are clogged with junk. The top of the lands looks shiny. The grooves not so shiny. I have been using jb and bore cleaner for a couple of days and I'm not sure it is working. Could it be that this barrel is just shot out? Or should I keep scrubbing the barrel?

Trapdoor barrels are three groove, and measuring a slug will not give the "actual" diameter.  If you can't see the grooves on the slug, yet you can see them in the barrel, you've probably got a good amount of lead buildup.  I normally use Shooters Choice bore cleaner (with smokeless powder) as it seems to work under and loosen light leading pretty well...but if your bore is heavily fouled with the stuff, you'll have to work on it mechanically.  You might want to try a .45 caliber Lewis Lead Remover on it, along with a good bore cleaner.

David

    Jimmy :

      There was recently a posting by some guy/s who were selling Bon Ami as a rifle bore cleaner, as well as a bath room tile cleaner, wash basin brightener, toilet bowl cleaner, and white wall tire cleaner.

      Doesn't appeal to me, but I thought I would send you an advance notice just in case they show up at your front door.

     Creedmoormatch

For lead removal it is hard to beat turpentine or alcohol on a tight patch.  I normally use some Kroil or other penetrating oil in the bore overnight then clean it out with liberal quantities of turpentine on a tight patched jag.  A stout rod, patched up and pounded thru works very well.  Substitue alcohol [denatured type] for the turpentine if you like, they both work well.

Keep on hav'n fun!
MikeT

+1 for the turpentine, stout rod and a tight patch. Trapdoor may complicate things because you have to pound the rod through and the only way you can do that is from the muzzle and you will need to take care not to damage the crown. On my high wall and roller I can clean from the breech and I use a Dewey rod. Once the patch is through the chamber and at the start of the rifling I place the handle of the rod on the floor and use the weight of the rifle to drive it through. The Dewey rod can take the punishment and the lead goes away.

+2 for the turpentine.  It has to be the Pure Gum stuff, not the 'distilled'.  And you might want to try this with the turp's for a severely leaded bore... plug the chamber, warm the barrel with a hair dryer and then pour hot turpentine in the bore.  Let it set overnight. 
Be careful not to burn the house down though when heating the turpentine. 

And if the turpentine fails to clean out the lead ... (You need to Login or Register to view media files and links)