I can do a full barrel roll with about 10% deflection of the rudder!
I've checked my controls, re-calibrated them, re-installed the baron, removed all weather, etc. etc. and still with about 10% deflection it just rolls and rolls and rolls. Elevators and Ailerons operate as expected. Other aircraft (and I've got a lot) all operate as expected.
Not sure what's going on to be honest.
Edit: Just tested your 310R and it has a similar tendency but much slower and very easy to control.