Yes, it is a good lube for cap and ball revolvers.
However, Crisco is also a good black powder lube, and you can buy several pounds of it for the same price 4 ounces of the commercial lubes cost.
At the top of this forum, there is a sticky entitled "Proper use of a cap and ball revolver" posted by Gatefeo. In section 9, he tells you how to make a great lube, which duplicates the commercial offerings, at a fraction on the price.