This means that you'll be able to search for NAICS codes directly (if that's your jam). We'll do the math; let's make better data on public procurement together.
Guns, over 300 mm
Breech Mechanisms; Training Gears; Power Drives.
Possible NAICS Codes
332994 – Small Arms, Ordnance, and Ordnance Accessories Manufacturing
332992 – Small Arms Ammunition Manufacturing
561210 – Facilities Support Services
541519 – Other Computer Related Services