Not sure what you consider heavy loads, but the TC load info for their 58 caliber rifle showed 120 grains of 2F under a 555-560 grain Maxi-Ball/Maxi-Hunter and patched round ball. Not exactly powderpuff loads in a less than 8 pound gun with a 26” barrel.I was also warned not to get heavy with the loads, as the thinner barrel was marginal on the safety side with heavy loads.
Curious what loads someone warned you to stay away from?