Just because you can search for captor mine doesn't mean all the information is correct or complete and searching is what actually caused all of my misunderstandings.

And every answer that is in this thread has been addressed in numerous other threads.  Find the discussions between Steve, Kurt, and Erik and you have the answers and some successful implementations.  Also some of the pitfalls.

Sensors and submunitions have simple answers but are tricky to implement. 

Charlie:  Yeah, but... Lazy. 

Right, so it seems that the best option with mines is to lay them individually on successive ticks rather than all at once.  If your mines last three months it doesn't matter if they expire one at a time over the course of 50 seconds, but that should be enough to make them count as ten separate salvos.  Which should, in theory, make the mines target ten separate contacts.

Just tried it and if the mines are in a salvo they combine their missiles into a salvo.  When you use the Launch Missiles at command in the task groups window a salvo is all missiles fired from a single ship and of the same type I would guess.

Ah yes that is it, I had thought a salvo was a group of missile fired from the same location at the same target traveling at the same speed.  Turns out its actually from the same fire control plus all the other stuff I would guess.  So after linking two size 5 launchers to one fire control and firing at the targets again only one target is destroyed and two missiles exploded.

Yes the missiles killed all the targets in one increment when using way points, and yes it took two increments if a ship was targeted.

I don't know what the deal is with the captor mines, maybe I don't understand how they work.  I thought both the first stage (buoy/drone) and the second stage (missiles) had to have sensors so they should work like a way point I would guess.  But maybe only the first stage needs sensors and then the missiles get their target before being launched.

Update
I made a mine with 3 of the size 5 missiles inside, fired 10 at a way point and once the missile got released and hit the target group (10 targets) all 30 missiles exploded.  So it looks like captor mines are treated differently then missiles.  Another odd thing is it took the missiles 30 seconds to move after they got released.

Update 2
The 30 second delay was from me using a way point to fire the mine at, also I don't have to turn off the the ships active sensors for the missiles to find a new targets it just takes 1 increment for the missiles to realize the way point got removed.  So remove the way point before the missiles get to it for best results it seems.

Update 3
After more playing around it seems that all the missiles in a second stage of a missile/mine are treated as one missile for attacking.  If I fire 10 of my drones at 5 targets there will be 5 groups of 3 missiles looking for targets.  In the Missiles in flight tab in the Comabt Assignments Overview window it also says 3x size 5 Anti-ship missile under missile type.

Update 4
Firing 1 drone at 10 targets only destroys 1 target.  I also tested it with missiles and buoys and they behave the same as the drones.  I also tried making a mine with missiles that had no sensors and the missiles self destructed as soon as they got released.

I just tested it out, in short no missiles are wasted in overkill.

This was my target for testing.
target class Cruiser    250 tons     23 Crew     48.6 BP      TCS 5  TH 0  EM 0
1 km/s     Armour 1-3     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 1     PPV 0
Maint Capacity 122 MSP    Max Repair 6 MSP

Fuel Capacity 50,000 Litres    Range N/A

This design is classed as a Commercial Vessel for maintenance purposes
I used 10 of these to fire the missiles.
Tribal class Cruiser    950 tons     110 Crew     155.4 BP      TCS 19  TH 60  EM 0
3157 km/s     Armour 1-8     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 1     PPV 5
Annual Failure Rate: 7%    IFR: 0.1%    Maint Capacity 102 MSP    Max Repair 30 MSP    Est Time: 9.21 Years
Magazine 21   

Ion Engine E9 (1)    Power 60    Fuel Use 90%    Signature 60    Armour 0    Exp 5%
Fuel Capacity 50,000 Litres    Range 105.2 billion km   (385 days at full power)

Size 5 Missile Launcher (1)    Missile Size 5    Rate of Fire 75
Missile Fire Control FC15-R5 (1)     Range 15.5m km    Resolution 5
Size 5 Anti-ship Missile (4)  Speed: 15,000 km/s   End: 22.2m    Range: 20m km   WH: 9    Size: 5    TH: 50 / 30 / 15

Active Search Sensor MR5-R5 (1)     GPS 105     Range 5.2m km    Resolution 5

Missile to hit chances are vs targets moving at 3000 km/s, 5000 km/s and 10,000 km/s

This design is classed as a Military Vessel for maintenance purposes
This missiles had 1 MSP of res 5 active sensors.

I fired 10 missiles (one salvo) at a task group made of 10 targets.  When the missiles reached their target one missile killed one target, then in the next 5 sec increment the 9 remaining missiles killed the 9 remaining targets.

I also did a second test where I fired missiles at a way point by the target task group and again 10 missiles killed 10 targets.  I actually had 2 salvos sitting at 2 different way points and 9 missiles got used from one salvo and 1 from the other.

I don't know if this is a bug or not but I had to turn off the active sensors on my ships to get the missiles sitting on the way points to pick up new targets.

Not quite, All of the missiles in the salvo that actually destroy the target will be gone.  Other missiles arriving in the same 5 second tick will not retarget then.  On the next 5 second tick they do retarget if they have some onboard sensor capability.  The problem with this is they are usually fairly small sensors, and the target may have moved out of range of their detection.

Brian

But other salvos arriving in the same tick will not explode without retargeting?

So, for example, say I have a wave of five bombers, each of which launches two missiles with onboard active sensors at a waypoint close to a (let's assume stationary) enemy fleet of five ships.  Let's assume it takes three missiles to destroy one of the target ships and let's assume every missile hits. Maybe they're shipyards or something.  Whatever.

The missiles get to the waypoint and lock on to the first target, ship one.  So, the first salvo hits ship one, doesn't destroy it. The second salvo also hits ship one, the first missile destroys it. The second missile in salvo 2 is then wasted? What about salvo three? Does it not impact anything this tick?  Does it self-destruct?  Will it retarget ship two next tick? Does that mean these missiles will hang around near the waypoint, targetting a new ship each five seconds, until they're all gone?

Sorry about all the questions, I've never used missiles with onboard sensors before, so I'm completely confused as to how this works.

Not quite, All of the missiles in the salvo that actually destroy the target will be gone.  Other missiles arriving in the same 5 second tick will not retarget then.  On the next 5 second tick they do retarget if they have some onboard sensor capability.  The problem with this is they are usually fairly small sensors, and the target may have moved out of range of their detection.

Brian

That usually only applies to AMM. Chances are a ship is still in range. And don't forget you can modify the resolution of the missile scanners.