A pair of precision-machined headspace gauges, likely British military issue, designed for armourers and ordnance personnel for setting or checking headspace clearance on small arms — particularly Bren LMGs and Lee-Enfield rifles. The serial numbers (R9393443) and distinct graduated scale (from 0 to 33) suggest factory calibration and batch-controlled production. The gauges are nickel or chromed brass for durability. Items like these were essential for armourers to ensure proper chamber fit and safe operation during field maintenance. The design is typical of mid-20th century British ordnance tools.