This is a 190 grain swaged bullet with cupped base and a hatch-mark bullet retention pattern on the bearing surface. They are coated with some sort of lubricant- probably moly. The nose is rounded like a ball to gain optimum fit to loading rams the base is rebated to allow the bullets to seat in the chambers. Seating is in a straight line with no more distortion than desirable and the same for all bullets.
This one is sized .457 and should work in Ubert Chambers-Possibly a bit large for pietta but will likely work in those too. I ordered them for the Ruger Old Army- a revolver set up around .457" balls and bullets. They loaded in a straight line and the optimum load provided a five shot group of 1.8" at 60 feet. Best consistency among loads tested was identical volume of Hodgdon's H777 to 40 grains of black powder.
Chronographed velocity/ calculated energy was:
40Gr./Vol. H 777 1066 fps 51fps spread 479ft/lbs
Other combinations provided good accuracy but larger extreme spreads. These bullets in both this diameter and 36 are as accurate or almost as accurate as round ball and provide optimum downrange energy
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