Here is the full list of all 30 Warhammer 40,000: Battlesector achievements worth 1,000 gamerscore.
Unlocked a Tier 3 node in a tech tree
Unlocked a Tier 1 node in a tech tree
Unlocked a flying unit
Scored a critical hit with a chainsword
Killed a Tyrannofex
Killed unit with a flame weapon
Completed the tutorial
Healed an ally
Killed an enemy unit with a grenade
Scored a critical hit with a bolter
Used the fallback command
Used the interact command
Complete Act One
Complete Act Two
Complete the Age of Crimson Dawn campaign
Unlock an Adepta Sororitas unit
Call in a Stormraven missile strike
Kill a Genestealer
Unlock a Tier 5 node in a tech tree
Complete any campaign mission using only melee weapons
Clear Kemrender of infestation nodes
Collect Gallian's staff
Recruit a Baal Predator
Recruit a Furioso Dreadnought
Win a skirmish battle against Blood Angels
Kill a Trygon with pistol
Kill a Hive Tyrant in a multiplayer game
Kill a Blood Angels Lieutenant in a multiplayer game
Trigger the Volatile ability
Sacrifice all Death Company units at Wind River Canyon