Thread: 6.5x55 barrel lenght ?

Ive been researching about how short you can go with a 6.5x55 barrel without dramatically effecting ballistics.
All the talk seems to be about how the .308 is probably the most efficient in shorter barrels ,and the results in a few of the other popular calibers , but Ive struggled to find out much about the Swede .
Does anyone know or have a link to info on shortening the Swedes barrel lenght and the subsequent ballistic effects .
How far is to far ?

Ken