Special Weapons Squad
Special Weapons Squads are Imperial Guardsmen given the honor to wield expensive and rare weapons that will fuck up the opposing side horrendously and hopefully not themselves sometimes. Many regiments maintain six-man squads of specialists armed and trained in a variety of roles.
Some are sniper squads, working in three two-man teams of sniper and spotter with the former armed with Sniper Rifles for taking out enemy commanders. Others are combat engineer teams, meant to clear trenches and destroy enemy fortifications with Demolition Charges, Flamers, Plasma Guns, Meltaguns and Grenade Launchers. These squads will often be attached to other platoons to provide them with their expertise.
Catachan Devils are often an entire regiment of Special Weapons Squads, more particularly in demolition charges, blowing up tanks and out-Krooting the Kroots, turning the tables around where the hunter becomes the hunted. Next time don't ask the Catachans where they got the meat from and why it strangely tastes like chicken. The answer will surprise you.
Combat engineers are particularly feared by the enemy and can clear out bunkers with gouts of lethal Promethium flame. Some of these specialists can act as anti-tank units using the aforementioned Melta or Plasma Gun.
If you want to take out those pesky TEQ's but also don't want to suffer the mobility disadvantage of a Heavy Weapons Squad, then the Special Weapons Squad with its wide range of destructive weaponry would do the job. Other than these weapons, SWS are equipped with Flak Armor, a backup Flashlight, some grenades and a combat knife.