American US, WW1, 37mm Pom-Pom Inert Round — 1916 Dated Case with 1917 Dated Marked Projectile, Inert

*American US, WW1, 37mm Pom-Pom Inert Round — 1916 Dated Case with 1917 Dated Marked Projectile, Inert*

A composite WW1-era 37mm Pom-Pom round, comprising a US-manufactured brass cartridge case dated September 1916 and a detachable projectile, dated March 1917 produced by the American-based Bethlehem Steel Company for British use. The projectile features a copper driving band and clearly stamped base markings. While not originally paired in service, the components have likely been combined post-war, a common practice among collectors for display purposes. Overall height approx. 16.5 cm, base diameter 4.4 cm.

Headstamp markings (case):
37-85 – Calibre and case length (37mm x 85R)
PDPs 77 – German manufacturer code: Polte Armaturen- und Maschinenfabrik AG, Werk Magdeburg, Factory 77
9.16 – Date of manufacture: September 1916
R – Likely inspector or lot mark

Projectile base markings:
B.S.C – Bethlehem Steel Company
37MM – Calibre
LOT 15 – Lot number
3-17 – Date March 1917

Historical Note:
The 37mm Pom-Pom round represents a significant leap in rapid-fire, automatic artillery systems that emerged in the late 19th and early 20th centuries. Initially developed by Maxim-Nordenfelt, the QF 1-pounder and its 37x85R variant saw combat use during WW1, particularly in anti-aircraft and anti-tank roles. Both the Allies and Central Powers utilised variations of this calibre, and the design laid foundational principles for future autocannon development. This round brings together two key aspects of WW1 autocannon development. The brass case is a German 37x85R, dated 9.16 and made by Polte of Magdeburg, a leading supplier of ammunition to the Imperial German Army’s 37mm Maxim anti-aircraft and trench guns. The projectile was manufactured in March 1917 by the Bethlehem Steel Company of Pennsylvania, which supplied solid and high-explosive rounds for the British QF 1-pounder "Pom-Pom" autocannons. These guns were deployed by British forces on land, at sea, and in aircraft, particularly during the early years of the war. The mixed provenance of this round illustrates both the widespread production and post-war collector interest in these iconic shells.

*Condition*
The brass case shows age-related wear and patina, with legible markings and no major structural damage. The projectile exhibits a rusted driving band and oxidation at the base but remains well formed and free of explosive content. Interior of the case is clear and shows light corrosion. The two components fit together securely for display. Please see photographs as part of the condition report.

JAQCH_2697130525