Tactical Support Squad
Tactical Support Squads were a type of Space Marine Legion squad used during the Great Crusade and Horus Heresy era. Somewhere in between a Tactical Squad and a Devastator Squad, the Tactical Support Squad are considered by some to be the Marines' equivalent of the Special Weapons Squad.
Overview
These mobile fire-support units replaced their standard Bolters with more specialized weapons such as Rotor Cannons, Volkite Culverins, Volkite Calivers, Plasma Guns, Flamers, and Meltaguns. If you're a Dark Angel, you can swap those lame ducks for Plasma Burners and Plasma Repeaters. Tactical Support Squads operate in close order with their respective Legion's other troops, their supporting firepower enabling a Space Marine force to act with even more versatility and engage a wider range of targets on its own terms. Tactical Support Marines also went through various iterations of power armour. At first, all of them wore Mark II armour, but over time, more modern marks such as the Maximus-pattern and the beakie armour became commonplace. By the time of the Heresy, the Mark V became standard for not only Tactical Support, but also other Space Marine squads such as Tacticals, Assaults and Devastators.
Crunch
HH 1.0
They are your actual source of special weapons. 5-10 marines, and all of them, including the sergeant, have flamers that can be swapped for other special weapons (though note that all Legionaries MUST swap their flamers for the new weapon) depending on what specifically you want to do with them:
- For dealing with general Infantry, you can keep the standard Flamer. Just because it is the starting option doesn't mean it's bad, since few things can survive charging, or survive existing near a full unit of 10 flamers, and they're much better than Rotor cannons which don't even look good on paper. They're terrible against Astartes, even though they put out a lot of shots (3-4 per gun) they're only S3. There is no armour save to fail if you're not wounding anything. Never take them over their superior alternative unless your Legion boosts them somehow.
- For dealing with MEQ's you've got Volkite Calivers. Heavy weapons may seem odd in a Special weapons squad, but these guns hit 2 points harder than Bolters, with 2 shots at more than 2 times the Bolter's 2-shot range, and are FAR cheaper than Volkite Culverins in a Heavy Support squad. Additionally, attaching a Siege Breaker to this unit will let you camp an objective and absolutely ruin light armor. If there was a god that his sacred numeration was binary, this would be his cultist's weapons...whoa, wait... All of the above is pretty decent for MEQ's, but then we have the Volkite rule, allowing you to get even more wounds, for
25 pts, just like Rotor guns. Seriously, don't take Rotor guns. The only real disadvantage you have is not being able to shoot on the move so you're not very mobile, but for that you have Volkite Chargers, which hit a tad weaker than Calivers, are Assault 2, and have half the range, meaning they'll be more exposed to retaliation fire (they are outranged by boltguns). Plan how you use them accordingly (attached medics, transports, etc.). - For dealing with 2+ armour and/or making the unit look like a bigger threat than it actually is you've got Plasma guns, and boy are these puppies a reason to take this squad. It's one of the most expensive options, but given its ability to "Nope" squads of Terminators and the high amount of artificer armour in the field, it's worth taking, but make sure you deep-strike them and keep the squad down to a small size. Those points add up quick and anybody who sees five plasma guns in a unit will do everything they can to kill them. You can also take Melta Guns but given how much Armoured Ceramite is around (it ignores the extra D6) it won't help often besides ID'ing some commanders and Legion Specific 2-wound Terminators, so use them the same way you would a Plasma squad (and expect the same welcome).
- As suggested in the name, Tactical Support Squads have the Support Squad rule, meaning they cannot fill compulsory Troops slots. You'll need 2 other Troops choices before you can start filling up in this department.
- As with tactical squads, they can take an extra CCW for 2 points a pop. Naturally this is better with some weapon loadouts and some legions than others; typically you want to consider it for the closer ranged options, flamers are a bit of a toss-up because nothing you can hurt in melee will be willing to charge a squad armed entirely with flamers, but volkite chargers have to get within charge distance anyway and will usually appreciate being able to pick off any stragglers from their target in melee, and meltaguns will definitely provoke a counter-charge if they blow up a transport. You probably shouldn't bother doing this for a squad with volkite calivers or plasma guns since it's unlikely to matter, and should never give a squad rotor cannons to begin with so there's no need to consider this option for them.
HH 2.0
In this edition they're a 5-man Tactical Squad that all take Special Weapons. They can buy 5 more guys and come stock with Flamers but can swap them for Volkite Chargers for free or pay points for the fun stuff like Plasma Guns, Meltaguns or Volkite Calivers. They are a Support Squad, so they can't be taken as Compulsory Troops and they do not have Line, so they can't score. They are best used to support other troops in shooting stuff, which they can be very good at, but they can also purchase chainswords. Considering that a lot of those weapons put the users within charge range of the enemy, some Legions with particular advantages in melee ought to be able to find a use for their Assault weapons and try to mop up survivors with a follow-up charge. While probably not as effective as Heavy Support Squads equipped with bigger versions of the same guns, Tactical Support squads take up a far less crowded Force Org slot in comparison so can be a good compromise if you are trying to squeeze in more firepower but your HS slots are all taken.
- Volkite Chargers/Calivers are good anti-infantry weapons, though Breachers probably will get the most out of Volkite weapons and are the better unit overall, despite being more expensive.
- Despite Plasma guns taking a nerf in the new edition, most of the shots will still be AP2 thanks to Breaching (4+) making it a decent weapon to deal with TEQs with massed fire and several Legions get their own cool Plasma weapons they can replace them with.
- Meltaguns are the go-to for tank-hunting and TEQ slaying, but the short range of 12" or 6" for Armourbane (Melta), means the squad will likely need a transport to get them into firing range.
- Finally, Rotor Cannons are actually worth taking this edition as they've lost Salvo (because it got removed from the game all together) and they are now 30" Assault 4 weapons with Pinning and Shell Shock (1), meaning those Pinning tests are taken at -1 Ld, making them fantastic anti-horde/infantry weapons (especially when fielded alongside melee units).