I have shot heeled bullets from the 38 Kirst/Pietta Konversions with great result, HOWEVER, those work best with real FFFG Black Powder. Modern propellants require a brutal crimp with an OWBM heeled crimp die, and the case tear from the heavy crimp. With FFFG black, it takes very little crimp.
The better option is the Bear Creek 150 grain round nose, hollow base lead with 4.0 grains of Unique. With a modest roll crimp, it obdurates in the bore sufficiently to give passable groups