Many feel that no break-in is required.  Those that do see a need for break-in use methods similar to what you describe.

As for a 1 turn in 20 inch twist being too slow...what makes you say that?  Are your bullets keyholing?
If it is too slow, that would not depend on the type of powder being used.  It is the length of the bullet that makes the difference.  Heavy bullets are longer, and require a faster twist to stabilize.

Try shorter (lighter weight) bullets in your 1 in 20 barrel.

The Pedersoli Sharps has a twist of 1 in 18.  That should be adequate for bullets up to about 550 grains.
CM

Good morning, screwloose;

I pretty well agree with what has been said so far.  You said you have broken the barrel in with yellow bullets.  I have found that you need to clean ALL the brass out to get good results with cast.

Y'all be good.

horsefly

Tom,

  I'd say you were getting real good accuracy with smokeless, so don't see why you can't do as well with BP.

  I hope you're not using Alox with BP. ? I haven't tried it myself, but from reading other Forums, it appears as tho it lays in a tar like coating in the bore that's very hard to remove.

  Personally I'd use a 1-25 Tin/Lead alloy, and also try 1-20 & 1-30 just to be sure one of those doesn't shoot better in your gun.

  I don't have any experience with your bullet, but I'd say the MV you're getting now should work. A Lyman 457125 I have, that weighs 523 grs. shoots best at around 1200 fps to. Load is 66.5 grs. of Goex Cartridge with .170" compression.

  As for buying the Pedersoli...... Didn't know you needed an excuse to buy a new gun! 

PETE

screwloose,

I've broken in a Badger barrel using the method you suggested and I've broken in another Badger barrel by shooting only black powder in it.  I couldn't see any difference between the two barrels regarding accuracy.

feather