Millenium 7* makes the point that 35mm and similar guns cannot shoot down medium altitude (FL 15 or higher) drones. Leonardo a while ago developed the DRACO, based on the 76mm gun. I am wondering whether this would not make a decent SPAAG/FSV?

https://www.armyrecognition.com/weapons_defence_industry_military_technology_uk/draco_oto_melara_76mm_multipurpose_surface_and_c-ram_counter-rocket_artillery_mortar_system_2007144.html

If a drone is flying at FL15* or higher, it’s probably worth a missile?

Perhaps the gap in the market is a cheaper missile capable of knocking down relatively low performance aircraft rather than a more expensive gun?

A 3 inch gun ought to be effective to 30,000ft or higher though.

* FL15 would be 1500 ft, which seems a bit low. FL150, or 4500m?

Yup, FL150, sorry. And don't most MALEs fly around there? And the 76mm seems to reach that high. The SAAB 57mm reaches around 7500m

Yes, the 76mm ought to reach. The datasheet on the naval super rapid version states a 0.3rad 1sd dispersion, which would equate to 1.3m at 15000ft (straight up, it would be higher further away from the gun) so modern fire control ought to be able to one-shot something slow and predictable.

15000ft puts an aircraft out of range of most shoulder launched missiles, but to get that high the aircraft is probably worth hitting with something bigger.

Ukraine would like some, it seems:

 https://military-wiki.com/ukraine-wants-draco-76mm-spaag-may-deal-with-kamikaze-uavs/

Once thing that greater range does is expand the slant range so a wider area at a given altitude can be covered.

is anybody using them?

Also, I am wondering whether the Saab 57 mightn't be the better choice - lighter?

Are there any 57 mounted on SPAAG?

graylion said...

is anybody using them?

Plenty of people operating the 76 super rapid on warships, but I'm not sure that the SPAA version (Centauro Draco) is in use by anyone. 

graylion said...

Also, I am wondering whether the Saab 57 mightn't be the better choice - lighter?

Not integrated on a land platform though. The Draco might not be in service but it does at least exist. The 76mm will also give better range than the 57mm which would be important if you wanted maximum coverage with minimum vehicles.

Mounting a few on static/towable test stands could be quite effective for defending high value installations or sitting astride known approach routes.

RovingPedant said:

Plenty of people operating the 76 super rapid on warships, but I'm not sure that the SPAA version (Centauro Draco) is in use by anyone. 

Doesn't seem to be. I must admit that I really like the concept. 

graylion said:

Yup, FL150, sorry. And don't most MALEs fly around there? And the 76mm seems to reach that high. The SAAB 57mm reaches around 7500m

Oh god no!
You mixed up range with ceiling. The AA ceiling for the 3" is ~4000 with full caliber shell. The AA ceiling for the 57mm L70 is usually given as 5000 m with full caliber shells. Which is a bit optimisitic IMHO but its consitent with the advantage in MV the 57/70 has over the 3".
Because this is what matters most for AA ceiling for guns of shell weights measured in the kg range. Muzzel velocity. If the shells start faster they climb higher. ME plays a role too but effective ceiling does not scale linear with ME. There is apoint of dimishing returns that is reached ~5".
To really get AA guns in the 57 mm - 3" range to be effective behond 4000 m ceiling you need sub caliber shells, with proximity fuse, ideally guided and rocket assisted. At which point it comes down to what is cheaper overall. A gun based or missile based system?

schnuersi said:

Oh god no! You mixed up range with ceiling. The AA ceiling for the 3" is ~4000 with full caliber shell. The AA ceiling for the 57mm L70 is usually given as 5000 m with full caliber shells. Which is a bit optimisitic IMHO but its consitent with the advantage in MV the 57/70 has over the 3". Because this is what matters most for AA ceiling for guns of shell weights measured in the kg range. Muzzel velocity. If the shells start faster they climb higher. ME plays a role too but effective ceiling does not scale linear with ME. There is apoint of dimishing returns that is reached ~5".

According to Tony the AA celing of the 57/70 is 24,930 feet (7,600 m) in proximity fuze mode

http://www.navweaps.com/Weapons/WNSweden_57-70_mk123.php

Also Tony: 76/62 AA ceiling 13,200 feet (4,000 m), so there he agrees with you. 

But it looks like developing a SPAAG based on the 57/70 might be useful (stick that flapanel X-Band radar on it too)

I am also wondering whether adding a second stage to StarStreak might be useful.