muzzle loading
The muzzle characterized all nonportable firearms such as cannon and mortar.
astragal 
The moldings used to join the various sections of the barrel together.
trunnion 
Cylindrical piece used to rest the barrel on the carriage and to pivot it when setting up the shot.
wedge 
Device used to adjust and secure the barrel in a specific firing position.
second reinforce 
Part between the first reinforce and the chase and next to the trunnions.
first reinforce 
The thickest part of the barrel where the powder charge exploded.