Not a ball peen, but we often use a 6 oz claw hammer for putting frames together with the Hoffmann Dovetail joining system. Especially for those W0s...That's what happens when people start comparing ball peens...
Everybody starts bragging about how big their's is...
My little 12oz works just fine...usually!
Ya can't just post that without more details.... What is a blacksmith vise? What makes it different or how is it used different? Never seen one before.