Sig Sauer CALXMPX4B9G2 9mm 4.5in Caliber Exchange Kit (MPX Gen II)

Designed for the Sig Sauer MPX Second Generation platform, this item is marketed as the CALXMPX4B9G2 caliber exchange kit for 9mm Luger. Source records identify a 4.5-inch carbon steel barrel finished in nitride intended for use with MPX Gen II rifles. The component is intended to provide a chambering option for shooters running the MPX Gen II in 9mm.

Key Specifications

• Chambering is listed as 9mm Luger.
• The barrel length is 4.5 inches.
• Constructed from carbon steel.
• Surface treatment is a nitride finish.
• Model designation is CALXMPX4B9G2.
• Marketed as a caliber exchange kit.
• Intended platform compatibility is Sig Sauer MPX Gen II.
• Dimension attribute in source data is listed as Caliber Exchange.

For shooters looking to configure or adapt a Sig Sauer MPX Gen II platform to 9mm, this offering represents the manufacturer-listed CALXMPX4B9G2 option with a 4.5-inch carbon steel barrel finished in nitride. Its design and materials reflect standard choices for durability and everyday range use, providing a straightforward option for those equipping their MPX Gen II for 9mm shooting applications.