The barrels are Plain Twist, which Bernard was known to make
https://docs.google.com/document/d/1fMs-Mn60ei9QsRcHT5Urm_eHobzJnaDKZiP3FP0fXb0/edit

By the mid-1800s the tube makers were having trouble sourcing horseshoe stubs, and mostly transitioned to Plain Twist
https://docs.google.com/document/d/1BdbWHfJmr2EyvzcPybid7pwlEliH6m9pr1LxMESM3W0/edit