By themselves hammers bounce the same as strikers. The transfer bar doesn't help because
it still connects the hammer and valve stem as long as the trigger is pulled. You'd
have to let off the trigger in a couple of milliseconds to beat the bounce.
But these CO2 revolver hammers do bounce less (than say a 22xx striker) because usually
they're mated to in-line valves which require less force to open and have different
forces acting on them during firing. With a 90-degree valve you'll still have bounce.