The Kleenbore 37/40mm Heavy Duty Cotton Bore Mop is a specialised barrel maintenance attachment engineered for large-bore launchers. Built with 100% absorbent cotton wound around a heavy-duty steel wire core, this manual cleaning tool is designed to hold large volumes of bore cleaner, chemical solvent, or CLP (Cleaner, Lubricant, Preservative). It provides full-contact coverage down smooth or rifled launch tubes to soak stubborn carbon fouling, swab bores clean, and distribute an even coat of protective oil or lubricant prior to long-term storage.

Key Features

• Large-Bore Fluid Application: Dense 100% cotton construction holds generous amounts of solvent or lubricant for thorough barrel soaking and protective oil application.
• Heavy-Duty Construction: Built on a rigid steel wire core to withstand repeated passes through launch tubes without bending.
• Kit Integration: Serves as a direct replacement bore mop for the KleenBore Gas/Grenade Cleaning System.
• Standard Large-Bore Interface: Uses industry-standard shotgun and large-bore rod threading for direct attachment to compatible cleaning rods.

Product Specifications

• Calibre Sizing: 37 mm and 40 mm launcher bores
• Threading: American Standard #5/16-27 male thread
• Core Material: Heavy-duty steel wire
• Mop Material: 100% absorbent cotton
• Operation: Manual / unpowered

Who is the Kleenbore 37/40mm Heavy Duty Cotton Bore Mop for?

• Law enforcement tactical units — requires a dedicated 37/40mm bore mop sized for 37 mm and 40 mm gas and less-lethal launchers to distribute solvent and wipe down launch tubes after operational deployments.
• Correctional services armourers — maintains ordnance inventory by applying protective lubricants and preservatives across 37 mm and 40 mm launch platforms using standard #5/16-27 threaded cleaning rods.
• Military tactical units — utilizes a full-diameter cotton mop to saturate 40 mm grenade launcher tubes with CLP during routine weapons maintenance.

Less suitable for: calibres below 37 mm, which require smaller calibre-specific mops; standard rifle or pistol cleaning rods featuring #8-32 or 5-40 threads, which require a thread adapter; or breaking up stubborn, baked-on carbon and lead fouling, which requires a heavy-duty phosphor bronze bore brush.