That 100-9X score for the muzzle loader would indeed have been scored a 100-10X in a NRA pistol match. By NRA scoring rules, if the bullet even slightly cuts the line, it's in. This means it's easier to shoot a perfect score in NRA pistol than in NMLRA pistol where the center of the bullet hole has to cut the line to be in.
Otherwise, the 25 and 50 yard pistol targets used by the NMLRA are dimensionally identical to the 50 yard and 25 yard timed and rapid fire NRA bullseye pistol targets.
The NRA pistol matches use a separate target with smaller scoring rings for the 25 yard slow fire match which is not used by the NMLRA. That means that the .45 caliber modern target was shot in either a timed or rapid fire match.