Heavy Weapons in 40K

Heavy Bolter: Damage 4d8, Heavy, Range (80, 240), Ammo (100), Ignores AC from Armor (Carapace or weaker), Special*.

*Can use Deathwatch Special Ammunition

Rocket Launcher [heavy]: Damage Varies, Heavy, Range (100, 300), Ammo (4), Ignores AC from Armor (Carapace or weaker), Special*

*Frag: Damage 4d6, Range (Template or 20ft), DEX save vs DC=8+proficiency bonus+DEX mod for Half, Ignores Cover
*Krak: Damage 6d6, single target only

Heavy Flamer [heavy]: Damage 6d6 Fire, No attack roll, Heavy, Assault, Range (Template), Ammo (10), DEX save vs DC=8+DEX mod+proficiency bonus for Half, Ignores Cover, Special*

*Catch fire: Damage 1d6 Fire per round until saved

Plasma Cannon [heavy]: Damage 6d6, Template, Heavy, Range (120, 360), Ammo (20), Ignores AC from Armor (Terminator or weaker), Special*

*Gets Hot: DC12 DEX per consecutive shots in same rounds, or take equal damage
*Effect lingers for 1d3 rounds  

Multi-Melta [heavy]: Damage 8d8 Melta, Heavy, Range (40, 120), Ammo (5), Ignores AC from Armor (Terminator or weaker), Special*

*Ignores resistances [Melta]
*Deals double damage vs vehicles and buildings if in 20ft of target  

Assault Cannon (Terminator only) [heavy]: Damage 10d4, Heavy, Range (120, 360), Ammo (100), Special*

*Target suffers extra d4 damage for each point the attack roll exceeds his AC

Conversion Beemer [heavy]: Damage Varies, Heavy, Range (200, 600), Ammo (5), Special*

*1d6 Light damage for every 10ft of distance from the opponent its fired at
*servo harness mounted only

Lascannon: Damage 10d6, Heavy, Range (120, 360), Ammo (5), Ignores AC from Armor (Terminator or weaker).