Modular cylindrical lockset

A key cam, comprising:

• a shell extending along a longitudinal axis defining a proximal direction and an opposite distal direction, the shell comprising:
• a proximal wall defining a first bowtie opening, wherein the first bowtie opening is defined in part by a pair of shell teeth;
• and
• a body portion extending distally from the proximal wall, the body portion defining a lug opening;
• and
• a plug movably mounted in the shell, the plug comprising a second bowtie opening, a shoulder, and a cam surface, wherein the second bowtie opening is defined in part by a pair of plug teeth;
• a stem movably mounted in the shell, the stem comprising a cam rider operable to engage the cam surface;
• a lock control lug movably mounted in the shell between the proximal wall and the shoulder, the lock control lug including an arm that extends into the lug opening;
• and
• a spring engage between the proximal wall and the lock control lug thereby urging the lock control lug into engagement with the shoulder.