Timmymagic wrote:Don't forget the Bushmaster Super40 also has 3P rounds...switch the gun out on a DS30M and you're approaching 40mm Bofor's capability, add in a pannier of Martlet on the side and you're exceeding it...Quite why the RN is buying Bofors 40mm I have no idea, its not as if its a new system to the RN..we had them for 70 years..
But still, US Navy selected 30mm version of MSI turret. So, presumably, its cost difference is significant, I guess? These turrets are for general use, to be shot frequently. AAW is a small fraction of their task. Everyday cheapness with normal "dull" ammo prevails everything in this kind of weapons, because the turret is ubiquitously equipped from RFA vessels to QECVs (and US Navy ships to USCG cutters, in near future).
The Bofors/Bushmaster-IV's 40x365mm rounds are significantly larger than 30x178mm rounds (very different from 40x180mm rounds for Bushmaster-II's 40mm-option). Their "dull" rounds must cost very different. For the 30x178mm rounds, US involvement will make its ammo-cost significantly cheaper, as well.
Surely the charge within the air-burst shells differs a lot between 30x178mm and 40x365mm, may be by a factor of 4? But, I do not think its control timer shares a large space, its quite simple system. If the 30x178mm air-burst rounds are 4-times cheaper than Bofors 3P (which is likely because the latter has also proximity fuses), just shoot 4 times more rounds. You can do it, because the 30x178mm rounds are cheaper.[EDIT] Not directly related to this discussion (MSI SeaHawk 30mm vs Bofors 40mm Mk.4 turrets), but, can MSI SeaHawk turret handle Bushmaster IV 40 mm cannon? It is much larger (in recoil) than Bushmaster II 40mm option. Are there any info?
As for 57mm I'm sure its a good gun, but again it has a competitor, 76mm. Again bigger round, bigger airburst and easier to integrate guuidance (which already exists in the real world, ulike MADFIRES). A 76mm can also stop a ship..., but despite Leonardo marketing I remain entirely unconvinced about its capabilty at NGFS...
No big objection, but I do think 57mm has some clear merit against 76 mm. If not, there is no reason why US Navy moved out from 76mm to 57 mm recently
. 76mm DARTS rounds are interesting, but looking the movies of its guidance, its just a laser CLOS system. The shell needs to go strait, cannot be in ballistic trajectory, which means significant air drag is always there for control. Not saying it is bad, but just saying a gun-based guided ammo will not be good against highly maneuverable ASMs. And, CAMM is there for it. Thus, for me, DARTS rounds are within the "nice to have" regime.
Again, not saying 76mm is bad. Just saying I see no big merit against 57 mm, and there is no surprise that US and UK selected the 57mm gun. Good rival, but neither prevails.