Anybody familiar with the Jonathan Browing mountain rifle made by Browing.  From what I have found out, they were only made for three or four years in the late 70's to early 80's.  I have the opporunity to swap for this one.  It appears to have a ladder style rear sight (I think they came with buckhorn style sights) and a tang mounted adjustable peep rear as well.  It is .50 cal and seems to be in very nice shape.  Are these good shooters (with patched round ball)?