Interesting info here
http://books.google.com/books?id=LQ...ts=XyDSosx73R&sig=vXy8YWyK2Ec1cf49QrmBZvOWv6s
It confirms something I'd always figured about the killing power of B&P revolvers being out of proportion to their velocity and energy figures.
The deformations of the round ball during the loading process and initial slugging effect of the blast and forcing cone, produces a wide short slug which dumps energy into the target much faster than conventional conical bullets.
Other sources confirm that powders available in the sixties and 70's often gave better performance than most brands of BP available today.
Old records indicate that 18th and 19th century highest quality BP gave much better performance than commercial and military grades.
The best back then was the French glazed powder.
According to 16th century records Cannoneers of those days mixed their own powder, which called for red wine as a solvent. When the wine dried it left a bio chemical glaze on the powder grains which made them moisture resistant, and the grains burned more evenly.
The cannoneers soon learned than instead of using the wine as a solvent they could drink the wine then urinate into the mixing pot. The bio chemicals came out in their urine and had the same effect.
The type of wood used when making the charcol was also a factor, Dogwood was the best.
I figure modern BP is made using less esoteric materials. Probably more chemically pure, but often contaminants are the key to getting the best performance.
My own experiances with the Walker indicate that its performance appears to be greater than the .357 on the targets I've used.
The Walker we used held a lot more than 60 grains of FFFG. closer to 75 under a round ball.
I often drill the bottom of the chambers deeper and closer to flat bottomed on BP revolvers I've owned and the Walker I'd worked on.
I'd noticed most BP cylinders don't appear to be as deep as patent drawings indicate, and theres almost always nearly twice the depth of the nipple holes unused.
I grind a suitable sized drill bit to a flat point and chase the chamber down to remove what I consider excess metal. Best to be sure the locking notches aren't cut too deeply first.
This Walker dropped it lever on a regular basis even before the modifications, so I installed a lever latch and its mating fixture from an old Navy barrel stub.
I also installed safety pins to the rear of the cylinder.
PS
Nice Colt McGunner.
Suppose they taste like chicken 
