There may be more at play than just velocity. Most target rifles tend to have longer barrels.
I have a CZ-452 with a 29" barrel. It is extremely accurate, though not moreso than the Biathlon Basic that I have which has an 18.5" or so barrel. I like the sight radius the longer barrel provides with iron sights. The BB has no option for iron sights. I wonder if the BB would be even *more* accurate with a longer barrel? They shorten the barrel on this model, probably just hack off the mount for the front sight, add weaver mount and cheap stock and *done* one Biathlon Basic. They are a great gun however.
Was that a digression or what....
- Makarov