Diehl and BAE Systems Agree to Put German 127 mm Guided Rounds Into the Mk 45 Mod 4 Naval Gun
Überlingen, 3 August 2026
Key points
- Diehl Defence and BAE Systems signed a memorandum of understanding on 3 August to develop integrated maritime defence solutions jointly
- The initial focus is integrating Diehl's 127 mm precision-guided, long-range ammunition family with BAE Systems' Mk 45 Mod 4 naval gun — the latest variant of one of the most widely fielded five-inch mounts in service
- The parties will also examine integrating the IRIS-T missile family into BAE Systems launching systems for maritime use
- No contract value, no schedule, no launch customer and no qualification programme are named
- Diehl's 127 mm guided product is the Vulcano family; trade reporting places the round's reach at up to about 80 kilometres, a figure the release itself does not state
Diehl Defence and BAE Systems signed a memorandum of understanding on 3 August to pair Diehl's 127 mm guided ammunition with BAE's Mk 45 Mod 4 naval gun, and to examine putting the IRIS-T family into BAE maritime launchers.
The Mk 45 Mod 4 is the reason this is worth recording. It is BAE Systems' current five-inch gun and the standard mount across the US Navy's surface fleet and a long list of allied navies, which means a round qualified on it is a round qualified for a large installed base rather than for one ship class. Diehl brings the ammunition side: a 127 mm family the release describes as precision-guided and long range — its guided 127 mm product is the Vulcano, developed with Leonardo, for which trade reporting gives a reach of up to roughly 80 kilometres. The release itself puts no number on it.
The second strand is a launcher question rather than a gun one: whether the IRIS-T family can be integrated into BAE Systems launching systems for maritime application. IRIS-T is Diehl's short-to-medium-range air-defence family, already navalised in German service.
What the document is not should be read plainly. A memorandum of understanding commits neither party to fund a qualification campaign, and gun-ammunition qualification is the expensive, multi-year part of exactly this kind of pairing.
This is a route to market that does not require a shipbuilding programme. A German round certified on an American-designed mount reaches navies that will never buy a German hull, and it reaches them at the refit rather than at the order — which is a different and larger addressable market than the one German naval exports normally compete in. Großwald recorded the memorandum in Signal No. 115. The check is whether a funded qualification programme follows, and on whose gun range.
