You show 2.75" FFAR on one line and Hydra 70 on another. Hydra 70 is a 2.75" FFAR but the 2.75 isn't always a Hydra 70.
The difference in rocket types is the motor. The older variant is the Mark 40 (Mk 40). The newer rocket that came around in the mid to late 80's was the Mark 66 (Mk 66) that picked up the nickname Hydra 70 after the program office that developed it. Both are 2.75" rockets. The maximum range of the Mk 40 was about 9000m and the Mk 66 was 11,000. Both had an effective range of 6000m since that was the limit of our Fire Control Computer and were identical in size. The Mk 66 is extremely fast with a flatter trajectory and shakes the AH-1 pretty violently when fired en masse from a hover. We probably ran out of Mk 40's by the early 90's since they weren't being produced anymore once the Mk 66 came online.
Each rocket uses a variety of warheads that can fit on either one. The most common is the 10 lb HE warhead. There were still some of the older Vietnam era 17 pounders (He) at that time in inventory. Those things could knock the turret off a tank.
Then there are the Flechette rounds...very, very nasty with a fixed range of 1200m. Then there was one of my favorite, the Willy Pete or WP for White Phosphorous. Then we had Proximity fuzed He, not good for diving fire as I found out one time when the aircraft set off the prox right in front of me. There was the Illum round or Flare, both white and IR types (for NVG use). Finally we have the MPSM for Multi-Purpose Sub Munition. This was developed at the same time as the Mk 66 and as far as I know was never used on the Mk 40. It has 7 submunitions inside each rocket. Extremely effective against armor out to 6000m.
There is no real minimum range on these, but other than the Flechette warhead, all the others had programmable ranges out to 6000m.
On a side note, rockets take a lot of practice to get proficient with despite having computerized aiming reticles and laser ranging, but once you get the hang of it, you can be pretty effective. Some methods were more of an artform, like deflection shooting, since the FCC couldn't take that type of firing into account.
If the aircraft was equipped with 19 shot pods, you could carry up to 3 different types of rockets, you just had to dial in the proper warhead/rocket combo into the Rocket Management System in the cockpit and either dial in a range or either use the laser or use a 15 second countdown in which case the RMS did a continual update based on speed, attitude, altitude, range, etc.
The rockets could be fired singly, in pairs, quads, or all at once with just a few milliseconds separating each rocket firing. So if you had all 4 19-shot pods (which was rare), and fired what was referred to as Quads-All (an RMS selection), that would be 76 rockets all impacting together in a single kill zone. That's 3 battalions worth of artillery impacting all at once from a single aircraft and we rarely fired single aircraft. Typically a dedicated attack could use 6 or more aircraft and if it was a battalion level operation as many as 18-21 might be used.
I do have all the Mark nomenclatures for the various warheads. I would have to go dig out my operators manual (-10) out of my basement if anyone wants them.
Needless to say they were a lot of fun to fire. Boy how I miss the smell of cordite in the morning
