British, WW1- c. 1915, Mills No.5 Mk I Hand Grenade, Cutaway, with early Mills Munitions Co Patent-Marked Base Plug, Inert

*British, WW1- c. 1915, Mills No.5 Mk I Hand Grenade, Cutaway, with early Mills Munitions Co Patent-Marked Base Plug, Inert*

An original British First World War Mills hand grenade, Pattern No.5 Mk I, dated 1915, presented as a factory or ordnance cutaway instructional example. The grenade retains its characteristic cast-iron segmented “pineapple” body, with a large vertical cut exposing the internal striker mechanism, spring, and detonator channel. The cutaway is cleanly executed and clearly intended for training or display purposes rather than post-war souvenir cutting.

The grenade is fitted with its original brass base plug, crisply stamped and partially legible, bearing the correct early-war markings including the model designation, manufacturer, and a stack of 1915 patent numbers. The external surface shows honest age-related corrosion and wear, consistent with genuine wartime manufacture and service handling. No explosive content is present, and the example is fully inert.

The base plug is stamped as follows:
-No 5 M (indistinct)
-3 (indistinct), Broad Arow
-PATENT No
-2111/15
-2468/15
-3559/15
-7636/15
-Mills Munitions Co,
-Birmingham
This fully marked early No.5 base plug, with the spelled-out manufacturer’s name and complete stack of 1915 patent numbers, represents an early and comparatively uncommon production variant, rarely encountered when compared with the later simplified Mills base plugs produced in vastly greater quantities.

Historical Note:
The Mills bomb was the first successful modern fragmentation hand grenade adopted by the British Army and became one of the most iconic weapons of the First World War. The No.5 Mk I, introduced in 1915, was the earliest widely issued version and saw extensive service during the early trench fighting on the Western Front.

To support rapid expansion of the British Army, large numbers of grenades were produced and instructional aids were manufactured for training soldiers, armourers, and ordnance personnel. Cutaway examples such as this were used to demonstrate the internal workings of the grenade, including the striker, spring, and detonator system, and were never intended for combat use. Surviving original cutaways are considerably scarcer than standard inert examples and are highly sought after by collectors and museums.

*Condition*
Good original condition overall. The cast-iron body shows surface corrosion, pitting, and wear commensurate with age and service. The cutaway edges are old and undisturbed. The brass base plug shows wear and oxidation but retains legible markings, including the model designation and stacked 1915 patent numbers. Please see photographs as part of the condition report.

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