Per Lyman's Black Powder Handbook, the .715 RB is 545 Grains.
With the Brown Bess as a test gun, Lyman reports the following results using G-O brand FFg grade powder (and .020" patch with Crisco as lube):
Charge Vel Muzzle Energy @ 100 yds
20 341 141 n/a
30 455 250 n/a
40 569 391 n/a
50 662 530 410
60 754 687 531
70 817 807 616
80 879 934 700
90 943 1075 782
100 1006 1223 859
110 1047 1325 913
120 1088 1430 966
130 1136 1559
140 1184 1703
150 1213 1778
Remember not to exceed Cabela's/mfg's specified maximum charge. Be safe.
This chart is unreadable. Sorry. First number is charge size, second is velocity, third is muzzle energy and last is energy at 100 yards.
[This message has been edited by 4V50 Gary (edited August 07, 2000).]