I never flew a C-130 but have been around them and have rode in many starting with the old A models. Some of the roll rate (or lack there of) you are
witnessing is due to slow speed, requiring large aileron inputs due to decrease airflow over the control surfaces. The old B-47 was horrible at slow
speeds requiring almost stop to stop control inputs to get anything out of her. But at normal cruise speed she would out run most of the fighters of
her day; beautiful aircraft for it's time.
Test Pilot for Boeing by the name of Boil or Boile did a high speed pass in a 707 during a football game in Calif.( 1960s ?) As he pulled up he did a
victory roll and nearly got fired too...or so his son told me..The story used to be there never was a Beoing aircraft that had not been rolled.
I have rolled the 727 and 737 (only in the simulator) and the 737 can be done quite easily (in a mini simulated airshow;especially the 300, 500, and
700 series) however the 72 will eat your lunch if you do not know what you are doing; wants to act like a lawn dart unless speed and power are
proper..The 737 take-off roll, break ground gear up, flaps up, and with proper speed and angle of attack is a no brainer, rudder is very effective...
BTY thanks for posting