British, Cold War Era-Dated 1979, 4.5 Inch Brass Naval Gun Shell Case, Royal Laboratory, Birtley

*British, Cold War Era-Dated 1979, 4.5 Inch Brass Naval Gun Shell Case, Royal Laboratory, Birtley*

Large 1979-dated British Royal Navy 4.5-inch naval gun cartridge case complete with its original MK N2 protective lid and broad arrow markings — a heavy, complete brass example ideal for military display.

Ths is a large and impressive brass naval cartridge case, one of the largest artillery shells used by the British Royal Navy. It is clearly marked to the base “45IN MARKS 3–5 GUNS,” indicating use with British Royal Navy 4.5-inch naval gun systems. Additional stamped production and batch details include Lot 222, the British Government War Department broad arrow, and the sequence “N5 / RLB / OOO” — where RLB denotes manufacture under Royal Laboratory, Birtley, and the three circles (OOO) represent ordnance inspection/acceptance marks. The case is dated 1979, placing it within Cold War naval service.

A significant feature of this example is the removable brass lid, which is stamped “4.5 MK N2.” This component served as a protective shipping plug, designed to seal the propellant (cordite) within the case, shielding it from moisture and accidental ignition during transport and storage in the ship's magazine.

The casing is of heavy brass construction, standing approximately 65 cm in height with a pronounced flared base and rolled neck. The inclusion of the screw-threaded lid adds to the mechanical detail of the piece. Overall weight exceeds 7.5 kg, giving a substantial display presence and reflecting thick-walled naval specifications.

Approx. Measurements – Top diameter: 11.3 cm. Overall height: 65 cm. Base diameter: 16.6 cm. Weight: over 7.5 kg.

History Note:
This case relates to British naval 4.5-inch gun systems, the long-serving medium calibre weapon fitted to numerous Royal Navy vessels during the post-war and Cold War period. The “Marks 3–5 Guns” designation references compatibility with the QF (Quick-Firing) 4.5-inch series used on destroyers and frigates from the late 1950s onward.

Unlike earlier fixed ammunition where the projectile and case were one unit, these guns often used separate-loading ammunition. The MK N2 lid was essential to this system; it kept the propellant charge secure until the moment of loading. In action, the explosive projectile was rammed into the breach first, followed by the brass cartridge case. The lid would be removed just before the case was hoisted to the gun bay, allowing the firing pin to strike the primer at the base and ignite the internal charge.

By the late 1970s, these guns formed the backbone of Royal Navy surface firepower for anti-aircraft, shore bombardment, and surface engagements. The presence of the broad arrow confirms official British government service issue, while the lot number and coded markings indicate strict batch manufacture and inspection control.

*Condition*
Good honest service condition with expected handling wear, light scratches, oxidisation, and areas of tarnish consistent with naval use. Markings remain clear and legible, including the stamped ordnance data to the base and the lid. The threaded neck and lid remain functional and structurally sound, with no major splits or damage noted. Pleas see photographs as part of the condition report.

Please call the office prior to purchase if you'd like to arrange collection.

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